Answer:
One of the most common ways of producing UV light is passing an electric current through vaporized mercury or some other gas. This type of lamp is commonly used in tanning booths and for disinfecting surfaces. The lamps are also used in black lights that cause fluorescent paints and dyes to glow.Explanation:
what is the symbol for Lithium, Iron, and Helium
Lithium=li
Iron=Fe
Helium=He
I don't say u must have to mark my ans as brainliest but if u think it has really helped u plz don't forget to thank me....
Answer:
lithium symbol=li helium= he and iron =i
Napisz równania reakcji chemicznych w formie cząsteczkowej, jonowej i jonowej skróconej. Podkreśl wzory soli trudno rozpuszczalnych i podaj ich nazwy.
palmitynian potasu + chlorek magnezu
zapis cząsteczkowy reakcji...………………..
zapis jonowy...…………………….
zapis jonowy skrócony...……………….
nazwa soli trudno rozpuszczalnej...……………..
oleinian sodu + azotan (V) wapnia
zapis cząsteczkowy reakcji...………………..
zapis jonowy...…………………….
zapis jonowy skrócony...……………….
nazwa soli trudno rozpuszczalnej...……………..
Answer:idioma equivocado ????
Explanation:
HELP!!!!!!!!!!!!!!!! PRETTY PLEASE !!!!!!!!!!!!!!!!
Answer:
B. 75.0 kPa
Explanation:
P1V1/T1=P2V2/T2
(x * 100 L)/(300 K)=(100 kPa * 50.0 L)/(200 K)
x=75.0 kPa
Answer:
24rq3r54
Explanation:
3t5q6tq6tq
Which is true of transition metals when moving from left to right on the periodic table
Answer:
D
Explanation:
Atomic radii decrease slightly and then start to increase.
Atomic radius of transition metals from left to right increases slightly then decreases. Thus it is not following the trend as for other periods. Hence, option c is correct.
What are transition metals?Transition metals are d-block elements in periodic table. starting from group 3 to group 12. Transition metals are called so because they are in between gases and metals in periodic table.
All transition metals shows varying oxidation states. For example, iron Fe shows +2 and +3 and copper shows +1, +2 and +3. Transition metals are malleable, ductile and are good conductors of heat and electricity.
From left to right in a row in periodic table, the atomic radius decreases and electronegativity increases. However, this trend is not systematic in the case of transition metals where, the atomic radii increases first and then decreases.
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Your question is incomplete, but your complete question probably was:
Which is true of transition metals when moving from left to right on the periodic table
The d sublevels are not filled across the period.
The cation radii become larger across the period.
Atomic radii increase slightly and then start to decrease.
Atomic radii decrease slightly and then start to increase.
how many electrons does phosphorus need to gain to have a stable outer electron shell
1
2
3
4
Answer:
3
Explanation:
Phosphorous valence is 5. so to get stable electronic configuration it has to gain 3 more electrons to its outer shell
Answer:
3
Explanation:
luckily, every phosphorus atom is looking to gain 3 electrons. It's a perfect match. But something to notice though, look how they have a bond with six electrons. That is called triple bond.
An empty graduated cylinder weighs 55.26 g. When filled with 50.0 mL of an unknown liquid, it weighs
92.39 g. The density of the unknown liquid is:
Answer:
.743 g/mL
Explanation:
Hopefully this helps :)
4. Which of these terms describes the process of acid rain wearing away limestone?
Acryptic erosion
B.chemical weathering
C.cryptobiotic weathering
D.chemical erosion
Answer:
B. Chemical weathering
Explanation:
Erosion is the process whereby the soil and rocks are washed away by wind, water, ice or gravity.
Weathering is the process of weakening and breaking down of rocks and minerals either by non-living (abiotic) or living (biotic) factors or by both, such as temperature changes, plants and animals, acids, salts and water, etc.
From the above definitions, it can be seen that acid wearing away limestone is a rock weathering process by a non-living agent, an acid.
Option A is wrong because the process is weathering
Option B is correct because an acid is a chemical and the process involved is weathering
Option C is wrong because an acid is non-living
Option D is wrong because the process involved is weathering
Given the formula representing a compound: What is the IUPAC name of this compound?
Answer:
2,2- dichloro-heptane
Explanation:
The IUPAC name of the compound is 2,2-dichloro-heptane
Formamide decomposes at high temperature. If 0.186 mol of formamide (HCONH2) dissociates in a 2.16 L flask at 400 K, what are the concentrations of all species present at equilibrium at 400 K? (hint: calculate concentrations first) (b) What is the total pressure in the container at equilibrium?
Answer:
a) [COHNH₂] = 0.001 mol/L, [NH₃] = [CO] = 0.085 mol/L
b) 5.59 atm
Explanation:
a) The decomposition reaction of formamide is the following:
COHNH₂(d) ⇆ NH₃(g) + CO(g)
The equilibrium constant of the reaction above is:
[tex]K_{c} = \frac{[NH_{3}][CO]}{[COHNH_{2}]} = 4.84 (400 K)[/tex]
The initial concentration of formamide is:
[tex] C_{COHNH_{2}} = \frac{\eta}{V} = \frac{0.186 moles}{2.16 L} = 0.086 mol/L [/tex]
Where: η is the number of moles and V is the volume
Now, in the equilibrium the concentration of all species is:
COHNH₂(d) ⇆ NH₃(g) + CO(g)
0.086 - x x x
[tex] K_{c} = \frac{[NH_{3}][CO]}{[COHNH_{2}]} = \frac{x*x}{0.086 - x} [/tex]
[tex] 4.84*(0.086 - x) -x^{2} = 0 [/tex]
By solving the above equation for x we have:
x = 0.085 mol/L = [NH₃] = [CO]
[COHNH₂] = 0.086 - 0.085 = 0.001 mol/L
Therefore, the concentrations of all species present at equilibrium at 400 K is [NH₃] = [CO] = 0.085 mol/L and [COHNH₂] = 0.001 mol/L.
b) To find the total pressure in the container we need to find first the constant Kp as follows:
[tex] K_{p} = K_{c}*RT^{\Delta n} [/tex]
Where R is the gas constant = 0.082 Latm/(Kmol), T is the temperature = 400 K and Δn = 1
[tex] K_{p} = K_{c}*RT^{\Delta n} = 4.84*(0.082*400)^{1} = 158.8 [/tex]
Now, the total pressure is:
[tex] p_{T} = p_{COHNH_{2}} + p_{NH_{3}} + p_{CO} [/tex]
The pressure of COHNH₂ can be found using Ideal Gas Law:
[tex] P = \frac{nRT}{V} = \frac{0.186 moles*0.082 L*atm/(K*mol)*400 K}{2.16 L} = 2.82 atm [/tex]
Using the equilibrium constant we can find the pressure of NH₃ and CO:
COHNH₂(d) ⇆ NH₃(g) + CO(g)
2.82 - x x x
[tex] K_{p} = \frac{P_{NH_{3}}*P_{CO}}{P_{COHNH_{2}}} [/tex]
[tex] 158.8*(2.82 - x) - x^{2} = 0 [/tex]
By solving the above equation for x we have:
[tex] x = P_{NH_{3}} = P_{CO} = 2.77 atm [/tex]
[tex] P_{COHNH_{2}} = 2.82 - 2.77 = 0.05 atm [/tex]
Thus, the total pressure is:
[tex] p_{T} = p_{COHNH_{2}} + p_{NH_{3}} + p_{CO} = (0.05 + 2.77 + 2.77) atm = 5.59 atm [/tex]
Hence, the total pressure in the container at equilibrium is 5.59 atm.
I hope it helps you!
If the mass of a certain block is 500g, what is the weight of the block?
______________________________
Solution,
Mass=500g =500/1000=0.5 kg
gravity(g)=9.8m/s^2
Now,
Weight= m*g
= 0.5*9.8
=4.9 N
So the weight of the block is 4.9 Newton
hope it helps...
Good luck on your assignment
_______________________
where are people mostly exposed to chemicals?
Answer:
people are mostly exposed to chemicals through their nose, mouth, eyes, and ears
Explanation:
they are the easiest way for anything, bad or good, to enter the body because people touch their face alot.
This might not answer what you were looking for but the other answer covered it pretty well so I thought I'd give you another angle to the question!
Hope this helps!!
How are ancient CO2 levels measured?
Answer:
Ancient CO₂ levels can be measured from
1) Air bubbles trapped in deep ancient ice cores (up to 800,000 years ago) or
2) Tree rings (up to 10,000 years ago)
Explanation:
The percentages of CO₂ concentration in the atmosphere from previous or ancient times are found by analyzing the CO₂ content in trapped air located in the deep ancient ice cores present in Antarctica and Greenland such as the EPICA Dome C cores
As the ice is drilled though, the air released from trapped bubbles are captured for analysis and the time frame for the captured bubbles can date back up to 800,000 years
Ancient CO₂ levels can also be measured from tree rings which provide ancient CO₂ levels up to 10,000 years
Can something be an acid and a base? Why and why not
Which of the following elements have the same number of valence electrons?
I. Nitrogen (N)
II. Oxygen (O)
III. Fluorine (F)
IV. Sulfur (S)
V. Selenium (Se)
What would the rate law be for the following reaction:
2 H2 + O2 → 2 H2O
a
Rate = k[O2]
b
Rate = k[H2]2
c
Rate = k[H2]2[O2]
d
Rate = k[H2O]2
Answer:
C. Rate = k[H2]^2[O2]
Explanation:
Rate law only cares about REACTANTS. Since, rate law can only be determined experimentally, I am assuming the given reaction mechanism is elementary reaction from which we can write the rate law.
Only H2 and O2 are part of rate law since they are reactants and also the coefficient in front of H2 goes as exponent on rate law to indicate the order of H2 in the reaction.
Rate= k [H2]^2 [O2]
According to the chemical equilibrium, the rate law for the given reaction is Rate = k[H₂]²[O₂] as the concentration is dependent on both the reactants.
What is chemical equilibrium?Chemical equilibrium is defined as the condition which arises during the course of a reversible chemical reaction with no net change in amount of reactants and products.A reversible chemical reaction is the one wherein the products as soon as they are formed react together to produce back the reactants.
At equilibrium, the two opposing reactions which take place take place at equal rates and there is no net change in amount of the substances which are involved in the chemical reaction.At equilibrium, the reaction is considered to be complete . Conditions which are required for equilibrium are given by quantitative formulation.
Factors which affect chemical equilibrium are change in concentration , change in pressure and temperature and presence of catalyst.
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What are the 5R principles of which we can make a difference in our environment?
Answer:
The 5R's are Reuse, Reduce, Recycle, Repair and Recover.
A 20 mL volume of a hydrochloric acid solution, HCl (aq), was placed into a beaker containing an appropriate
acid-base indicator. It was titrated with a solution of sodium hydroxide, NaOH (aq), until the endpoint was
reached. If 25 mL of sodium hydroxide solution with a concentration of 0.20 mol/L was used, what is the
concentration of the acid?
Select one:
a. 2.5 mol/L
O
b. 0.20 mol/L
C. 0.25 mol/L
d. 2.0 mol/L
Answer:
C- 0.25mol/L
Explanation:
Hcl+Naoh-Nacl+H2O
Ratio =1:1
0.2moles of Naoh in1000cm3 what about 25=(25×0.2)÷1000=
0.005moles
0.005moles in 20cm³ what about in 1000
(0.005×1000)÷20=0.25mol/L
According to the molar concentration, the concentration of the acid is 2.5 mole/liters.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.In case of 2 solutions, molar concentration is obtained as M₁V₁=M₂V₂, on substitution of values, M₁=25×0.20/20=2.5 mole/L.
Thus,the concentration of the acid is 2.5 mole/liters.
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Which of the following statements are true? Significant figures in a measurement are all measured digits, and one estimated digit None of the above Significant figures communicate the level of precision in measurements Significant figures are an indicator of the certainty in measurements
Answer: Significant figures in a measurement are all measured digits, and one estimated digit
Significant figures communicate the level of precision in measurements Significant figures are an indicator of the certainty in measurements.
Explanation:
Significant figures : The figures in a number which express the value or the magnitude of a quantity to a specific degree of accuracy or precision is known as significant digits.
The significant figures of a measured quantity are defined as all the digits known with certainty and the first uncertain or estimated digit.
Rules for significant figures:
1. Digits from 1 to 9 are always significant and have infinite number of significant figures.
2. All non-zero numbers are always significant.
3. All zero’s between integers are always significant.
4. All zero’s preceding the first integers are never significant.
5. All zero’s after the decimal point are always significant.
The true statements are
Significant figures in measurement are all measured digits, and one estimated digit
Significant figures communicate the level of precision in measurements Significant figures are an indicator of the certainty in measurements.
The following information should be considered:
The figures in a number that express the value or the magnitude of a quantity is known as significant digits.The significant figures of a measured quantity refers to all the digits known with certainty.Learn more: https://brainly.com/question/1979431?referrer=searchResults
Mitchell and his lab partner were conducting a titration experiment. Their goal was to neutralize 0.50 mol NaOH. How many moles of H2SO4 are needed to complete the neutralization? A) 0.25 mol B) 0.50 mol C) 1.00 mol D) 2.00 mol
Answer:
The answer is "Option A"
Explanation:
Given:
Moles in [tex]NaOH = 0.50[/tex]
The equation formula for [tex]NaOH[/tex]and[tex]H_2SO_4[/tex] reactions as follows:
[tex]2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O[/tex]
The reaction's stoichiometry:
If 2 moles of [tex]NaOH[/tex] react with 1 [tex]H_2SO_4[/tex] mole
Thus 0.50 [tex]NaOH[/tex] moles react with = [tex]\frac{1}{2} \times 0.50[/tex] [tex]H_2SO_4[/tex] moles
So, the final value is= 0.25
Name the following 3 structural formulas correctly, in order from left to right
Answer:
1. Methyl propanoate.
2. Propanol.
3. 2–pentyne
Explanation:
1. The functional group in this case is ester. We name ester by naming the group after the functional group (–COO) then followed by the parent compound with the name ending with –oate.
The group after the functional is methyl i.e —CH3.
The parent compound has 3 carbon i.e propane. The functional group replaces the –e in propane with –oate.
Therefore, the name of the compound is:
Methyl propanoate.
2. In this case the functional group is
–OH i.e alcohol.
The compound has 3 carbon i.e propane. The functional group replaces the –e in propane with –ol.
Therefore, the name of the compound is:
Propanol.
3. The triple bond represents the functional group in this case i.e alkyne. We'll give the triple bond the lowest low count by counting from the left. The triple bond is at carbon 2.
The compound has 5 carbon i.e pentyne since it contains triple.
The name of the compound is:
2–pentyne
When electrons are removed from the outermost shell of a calcium atom, the atom becomes
A)an anion that has a larger radius than the atom.
B) an anion that has a smaller radius than the atom.
C)a cation that has a larger radius than the atom.
D) a cation that has a smaller radius than the atom.
Answer:
A cation that has a smaller radius than the atom.
Explanation: when electrons are removed from the outermost shell of a calcium atom, the atom becomes a cation that has a smaller radius than the atom.
When electrons are removed from the outermost shell of a calcium atom, the atom becomes a cation that has a smaller radius than the atom. Therefore, the correct option is option D.
What is atom?Atom, the smallest unit of matter that may be separated without releasing electrically charged particles. It is also the smallest unit of matter with the characteristics of a chemical element. As a result, the atom is indeed the fundamental building component of chemistry.
The majority of the atom comprises empty space. The rest of the structure is made up of a positive-charged nucleus of neutrons and protons surrounding by a cloud of electrons with negative charges. In comparison to electrons, the lightest energized particles in nature, the nuclei is small and dense. When electrons are removed from the outermost shell of a calcium atom, the atom becomes a cation that has a smaller radius than the atom.
Therefore, the correct option is option D.
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what part of the brain helps you see and think
Answer:
Mark me brainliest
How does fuel burn in a diesel vehicle?
Answer:
it burns through oxygen gas.... through the process known as combustion.... combustion is the process of burning materials in the presence of Air
What is the mole ratio between NH3 and H2O in the following reaction:
4NH3(g)+ 6NO(g)----->5N2(g) +6H2O(l)
Answer:
1 mole of nitrogen (N2) reacts with 3 moles of hydrogen (H2) to form 2 moles of ammonia (NH3) ... 4 NH3 (g) + 5 O2 (g) --> 4 NO (g) + 6 H2O (g) ... Example: What is the molar ratio between Li and N2 in the following reaction
Explanation:
1 mole of nitrogen (N2) reacts with 3 moles of hydrogen (H2) to form 2 moles of ammonia (NH3) ... 4 NH3 (g) + 5 O2 (g) --> 4 NO (g) + 6 H2O (g) ... Example: What is the molar ratio between Li and N2 in the following reaction
at what temperature would 2.10moles of N2 gas have a pressure of 1.25atm and fill a 25.0 L tank
Answer:
[tex]\large \boxed{\text{-92 $^{\circ}$C}}[/tex]
Explanation:
We can use the Ideal Gas Law and solve for T.
pV = nRT
Data
p = 1.25 atm
V = 25.0 L
n = 2.10 mol
R = 0.082 06 L·atm·K⁻¹mol⁻¹
Calculations
1. Temperature in kelvins
[tex]\begin{array} {rcl}pV & = & nRT\\\text{1.25 atm} \times \text{25.0 L} & = & \rm\text{2.10 mol} \times 0.08206 \text{ L}\cdot\text{atm}\cdot\text{K}^{-1}\text{mol}^{-1} \times T\\31.25&=&0.09847T\text{ K}^{-1}\\T& = &\dfrac{31.25}{\text{0.098 47 K}^{-1}}\\\\& = &\text{181 K}\end{array}[/tex]
2. Temperature in degrees Celsius
[tex]\begin{array} {rcl}T & = & (181 - 273.15) \, ^{\circ}\text{C}\\& = & -92 \, ^{\circ}\text{C}\\\end{array}\\\text{The temperature of the gas is $\large \boxed{\mathbf{-92 \, ^{\circ}}\textbf{C}}$}[/tex]
What is the mass of a bone that has a volume of 80.0 cm3 and a density of 1.9 g/cm3 ?
Show the work in conversion factors format please!
Answer:
152
Explanation:
since it weighs 1.9 grams per [tex]cm^{3}[/tex] we get 80*1.9 which is 152 grams
50 points - I need this really soon! plz help
The pictured compound has which bond?
A.) C = C and C −C
B.) C = C and C −H
C.) C −Cand C −H
D.) C −C, C −H, and C −O
Answer:
C.
Explanation:
Butane (C4H10) has 3 C-C bonds in the carbon chain and 10 C-H bonds
Butane ([tex]C_4H_10[/tex]) has 3 C-C bonds in the carbon chain and 10 C-H bonds
What is alkane?Alkanes are saturated hydrocarbons. This means that their carbon atoms are joined to each other by single bonds.
Based on the diagram, butane is considered to be an alkane. It not only contains single covalent bonds, but also has carbon and hydrogen atoms present in its structure.
When comparing both structures to one another, isobutane is a branched chain, while butane is a linear chain.
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Which of the following is not sublimable? * 1 point Dry ice Calcium chloride Ammonium chloride
fasttttt
Answer:
Calcium chloride
Explanation:
Sublimation is the process whereby a solid substance is converted to gas when heat is applied or when exposed to an environment with a higher temperature.
Solid normally gets converted to the liquid phase before reaching the gaseous phase but these substances gets converted from solid straight to gas
Solid—> Gas
Dry ice( solid CO2) and Ammonium chloride undergo sublimation while Calcium chloride doesn't.
What is a solvent?
A.always water
B.the liquid in the solution
C.the substance in which the solute dissolves
Answer:
C. the substance in which the solute dissolves
Explanation:
There are two terms in this... the solute and the solvent. The way I learned how to remember this is with a little pirate analogy: The loot (stolen treasure) always goes in the vent. So, the soLUTE goes in the solVENT.
a solution of hydrochloric acid contains 1.5 moles of the solute in 2.0 liters of solution. calculate the molarity of this solution
Answer:
0.75 M
Explanation:
Molarity = moles of solute / liters of solution
so;
Molarity = [tex]\frac{1.5 Moles}{2.0 Liters}[/tex]
According to molar concentration, the molarity of this solution is 0.75 molar.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.Substitution in formula gives, molarity= 1.5/2=0.75 M
Thus, the molarity of this solution is 0.75 molar.
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