Answer:
Stretching is the lengthening and contraction is the shortening
Explanation:
Unless it's asking for eccentric as the stretching and concentric as the shortening
True or false. Law of action/reaction: for every action there is an equal and the same reaction. Pls don’t give me a link and tell me the answe
What is orbit? A. An increase in centripetal motion and mass friction. B. Resistance of an object to avoid friction. C. Gravity causing a curved path as an object tries to go straight. D. How well an object floats.
Answer:
C. gravity causing a curved path as an object tries to go straight.
What is the speed of sound in dry air at 20°C?
Many bones get their name from the bone they are
The elemental composition of propane gas (C3H8) is 81.68% C and 18.32% H by mass. What is the maximum amount of C3H8 in grams that can be formed from 160.0 g C and 160.0 g H
Molar mass of C3H8 = C 3 (12.01 g/mol) = 36.03 (g/mol)
H 8 (1.008 g/mol) = 8.064 (g/mol)
44.09 (g/mol)
74.6 g propane x 1 mole propane x 6.022 x 10
23
molecules
44.09 g propane 1 mole propane
= 1.02 x 10
24 molecules propane
A balloon is filled
with 35.0 L of
helium when the
temperature is
200K. If the tem-
perature rises to
450K, what is the
new volume of the
balloon?
Answer:
78.75L
Explanation:
According to Charle's Law:
V1/T1=V2/T2
35/200=V2/450
V2=(35*450)200
V2=78.75L
When NH3(g) reacts with O2(g) to form N2O(g) and H2O(l), 342 kJ of energy are evolved for each mole of NH3(g) that reacts. Write a balanced thermochemical equation for the reaction with an energy term in kJ as part of the equation.
Answer: [tex]2NH_3(g)+2O_2(g)\rightarrow N_2O(g)+3H_2O(l)+684kJ[/tex]
Explanation:
The skeletal thermochemical equation for the reaction is:
[tex]NH_3(g)+O_2(g)\rightarrow N_2O(g)+H_2O(l)+342kJ[/tex]
The balanced thermochemical equation for the reaction is:
[tex]2NH_3(g)+2O_2(g)\rightarrow N_2O(g)+3H_2O(l)+684kJ[/tex]
When 1 mole of [tex]NH_3[/tex] reacts with oxygen , heat released = 342 kJ
Thus when 2 moles of [tex]NH_3[/tex] reacts with oxygen , heat released = [tex]\frac{2}{1}\times 342 kJ=684kJ[/tex]
Help meee??
HNO 3 is an example of Select one :
Triprotic Acid
O Diprotic Acid
O Monoprotic Acid
Tetraprotic Acid
what is the mass concentration in ppm of NaCl of 0.01% mass/mass
A-10
B-100
C-10^3
D-10^4
E-10^5
Answer:
B-100
Explanation:
ppm is an unit of concentration that could be defined as the mass in mg of solute (In this case, NaCl) per kg of solution.
Now, a solution of NaCl that is 0.01% by mass, contains 0.01g of NaCl in 100g of solution.
To solve this question, we must convert the mass of NaCl to mg and the mass of solution to kg:
Mass NaCl:
0.01g * (1000mg / 1g) = 10mg
Mass Solution:
100g * (1kg / 1000g) = 0.10kg
The ppm are:
10mg / 0.10kg =
100ppm
Right answer is:
B-100The iodide in a sample that also contained chloride was converted to iodate by treatment with an excess of bromine: The unused bromine was removed by boiling; an excess of barium ion was then added to precipitate the iodate: In the analysis of a 1.54-g sample, 0.0596 g of barium iodate was recovered. Express the results of this analysis as percent potassium iodide.
Answer: The percentage of potassium iodide in the sample is 2.63 %.
Explanation:
The chemical equation for the reaction of iodide ions with bromine gas follows:
[tex]I^-+3Br_2+3H_2O\rightarrow 6Br^-+IO_3^-+6H^+[/tex] (i)
The chemical equation for the reaction of iodate ions with barium ions follows:
[tex]Ba^{2+}+2IO_3^-\rightarrow Ba(IO_3)_2[/tex] ......(ii)
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Given mass of barium iodate = 0.0596 g
Molar mass of barium iodate = 487.13 g/mol
Using equation 1:
[tex]\text{Moles of barium iodate}=\frac{0.0596 g}{487.13 g/mol}\\\\\text{Moles of barium iodate}=1.22\times 10^{-4} moles[/tex]
By Stoichiometry of the reaction (ii):
1 mole of barium iodate is produced by 2 moles of iodate ions
So, [tex]1.22\times 10^{-4} moles[/tex] of barium iodate will be produced by [tex]\frac{2}{1}\times 1.22\times 10^{-4} =2.44\times 10^{-4}moles[/tex] of iodate ions
By the stoichiometry of the reaction (i):
1 mole of iodate ions are produced by 1 moles of iodine ions
So, [tex]2.44\times 10^{-4} moles[/tex] of iodate ions will be produced by [tex]\frac{1}{1}\times 2.44\times 10^{-4} =2.44\times 10^{-4}moles[/tex] of iodine ions
Moles of potassium iodide = Moles of iodide ions = [tex]2.44\times 10^{-4}[/tex]
Since, the molar mass of potassium iodide = 166 g/mol
Using equation 1:
[tex]\text{Mass of potassium iodide}=2.44\times 10^{-4}mol\times 166 g/mol\\\\\text{Mass of potassium iodide}=0.0405 g[/tex]
To calculate the percentage by mass of a substance, the equation used is:
[tex]\text{Percent by mass}=\frac{\text{Mass of a substance}}{\text{Mass of solution}}\times 100[/tex]
Mass of a solution = 1.54 g
Mass of potassium iodide = 0.0405 g
Using above equation:
[tex]\text{Percent potassium iodide}=\frac{0.0405 g}{1.54g}\times 100\\\\\text{Percent potassium iodide}=2.63\%[/tex]
Hence, the percentage of potassium iodide in the sample is 2.63 %.
Expressing the results of potassium iodide in percentage = 2.63%
The chemical reaction of iodine ions with Bromine gas can be expressed as :
I⁻ + 3Br₂ + 3H₂O -- > 6Br⁻ + IO₃ + 6H⁺ ----- ( 1 )
Chemical reaction between iodate ions with barium ions can be expressed as : Ba²⁺ + 2IO⁻₃ ------> Ba ( IO₃ )₂ --------- ( 2 )
Step 1 : Calculate the number of Barium iodate moles
mass of Barium iodate = 0.0596 g
molar mass of Barium iodate = 487.13 g/mol
from equation ( 1 )
moles of Barium iodate = ( 0.0596 ) / ( 487.13 ) = 1.22 * 10⁻⁴ moles
also from equation ( 1 ) the moles of potassium iodide = moles of iodide ions
= 2.44 * 10⁻⁴
molar mass of potassium iodide = 166 g/mol
Next step : Determine the mass of potassium iodide
moles of potassium * molar mass
= 2.44 * 10⁻⁴ * 166 g/mol = 0.0405 g
Final step : Determine the percentage of potassium iodide in the solution
Percentage = ( mass of potassium iodide / mass of solution ) * 100
= ( 0.0405 / 1.54 ) * 100
= 2.63%
Hence we can conclude that potassium iodide in percentage = 2.63%
Learn more : https://brainly.com/question/3388761
Select the valid ways to make an ammonia/ammonium buffer for use in the laboratory. Mix equal volumes of 1 M NH3 and 0.01 M NH 4. Mix some volume of 1 M NH3 with half as much 1 M HCl. Mix equal volumes of 1 M NH3 and 1 M NH 4. Mix equal volumes of 1 M NH3 and 1 M HCl.
Answer:
The answer is "Option b and Option c".
Explanation:
This buffer is a buffer of ammonia and ammonium ion. Thus it requires the solution [tex]NH_3 \ \ and \ \ NH_4^{+}[/tex].
In point 1:
The solution containing [tex]NH_3 \ \ and \ \ NH_4^{+}[/tex] at 1M concentration would be given by mixing the two solutions. Thus, this buffer is a legitimate route.
In point 2:
It gives the ions you want but they are not the same.
In point 3:
[tex]1 M[/tex] [tex]NH_3[/tex] and [tex]1 M[/tex][tex]HCl[/tex] volume would not produce the same [tex]NH_3 \ \ and \ \ NH_4^{+}[/tex] concentrations. Therefore, this buffer isn't a valid route.
In point 4:
Some [tex]1 M[/tex] [tex]NH_3[/tex] volume and half [tex]HCl[/tex] . This offers the same rate as half.
What is the entropy of this collection of training examples with respect to the positive class B. What are the information gains of A1 and A2 relative to the training dataset For A3, which is a continuous attribute, compute the information gain for every possible split. C. What is the best split (among A1,A2, and A3) according to the information gain
The data set is missing in the question. The data set is given in the attachment.
Solution :
a). In the table, there are four positive examples and give number of negative examples.
Therefore,
[tex]$P(+) = \frac{4}{9}$[/tex] and
[tex]$P(-) = \frac{5}{9}$[/tex]
The entropy of the training examples is given by :
[tex]$ -\frac{4}{9}\log_2\left(\frac{4}{9}\right)-\frac{5}{9}\log_2\left(\frac{5}{9}\right)$[/tex]
= 0.9911
b). For the attribute all the associating increments and the probability are :
[tex]$a_1$[/tex] + -
T 3 1
F 1 4
Th entropy for [tex]$a_1$[/tex] is given by :
[tex]$\frac{4}{9}[ -\frac{3}{4}\log\left(\frac{3}{4}\right)-\frac{1}{4}\log\left(\frac{1}{4}\right)]+\frac{5}{9}[ -\frac{1}{5}\log\left(\frac{1}{5}\right)-\frac{4}{5}\log\left(\frac{4}{5}\right)]$[/tex]
= 0.7616
Therefore, the information gain for [tex]$a_1$[/tex] is
0.9911 - 0.7616 = 0.2294
Similarly for the attribute [tex]$a_2$[/tex] the associating counts and the probabilities are :
[tex]$a_2$[/tex] + -
T 2 3
F 2 2
Th entropy for [tex]$a_2$[/tex] is given by :
[tex]$\frac{5}{9}[ -\frac{2}{5}\log\left(\frac{2}{5}\right)-\frac{3}{5}\log\left(\frac{3}{5}\right)]+\frac{4}{9}[ -\frac{2}{4}\log\left(\frac{2}{4}\right)-\frac{2}{4}\log\left(\frac{2}{4}\right)]$[/tex]
= 0.9839
Therefore, the information gain for [tex]$a_2$[/tex] is
0.9911 - 0.9839 = 0.0072
[tex]$a_3$[/tex] Class label split point entropy Info gain
1.0 + 2.0 0.8484 0.1427
3.0 - 3.5 0.9885 0.0026
4.0 + 4.5 0.9183 0.0728
5.0 -
5.0 - 5.5 0.9839 0.0072
6.0 + 6.5 0.9728 0.0183
7.0 +
7.0 - 7.5 0.8889 0.1022
The best split for [tex]$a_3$[/tex] observed at split point which is equal to 2.
c). From the table mention in part (b) of the information gain, we can say that [tex]$a_1$[/tex] produces the best split.
Why is SpaceX likely to succeed in a mission to Mars?
A. It only hires expert NASA employees as its employees.
B. It takes more risks than NASA, which cannot afford them.
C. It is run by Elon Musk, who is determined to get to Mars.
D. It has fewer restrictions than NASA does.
Answer:
C
Explanation:
It is run by Elon Musk, who is determined to get to Mars.
All chemical reactions use reactants in a specific proportion or stoichiometry to regulate the amount of products produced. The __________ reactant is consumed completely during the reaction but some of the __________ reactant is left over.
a. limiting, excess
b. excess, limiting
c. proportional, ideal
d. chemical, stoichiometric
Answer: The answer is a. limiting, excess. I took the test.
Explanation:
Atoms in the same GROUP have the same...
A . Size
B. Temperature
C. Number of energy levels
D. Reactivity
Answer:
reactivity
Explanation:
for example atoms in group 7 react by gaining 1 electron to become stable but they do not have the same number of energy levels
20 points!
Which two structures produce energy that cells can
use?
A and B
B and C
C and D
D and A
Answer:
c and d
Explanation:
mitochondria and vacoule
Answer:
It is actually D and A
Explanation:
I took this assignment before on edge and the guy who said C and D is wrong
Which oficial the following organisms si not an autotroph
A. mushroom
B. grass
C. tree
D. moss
Answer:
A. mushroom
Explanation:
What is the molarity of the resulting solution when 300. mL of a 0.400 M solution is diluted to 800.
mL?
Answer:
0.150M
Explanation:
hope it helps!!!!!!!!!!!!
The molarity of the resulting solution when 300. mL of a 0.400 M solution is diluted to 800 mL is 0.15M.
Molarity is defined as the ratio of the number of moles of solute present in a solution, to the volume of that particular solution in litres.
It is calculated by using the formula
M₁V₁ = M₂V₂
M₁= initial molarity of the solution
V₁ = initial volume of the solution
M₂ = final molarity of the solution
V₂ = final volume of the solution
Given data,
M₁ = 0.400 M (initial molarity)
V₁ = 300 mL (initial volume)
V₂ = 800 mL (final volume)
Substituting the values we get
M₁V₁ = M₂V₂
.4× 300/800 = M₂
Therefore, molarity of the resulting solution = .15
To know more about molarity here
https://brainly.com/question/33791250
#SPJ2
which of the following, when dissolved in water, forms a weak acid.A. HNO3B. HClO4C. HBrD. HClOE. NH3
Answer:
The weak acid is - E. [tex]NH_3[/tex]
Explanation:
Ammonia is a strong base, which in turn make it to be a weak acid.
As, the rest of the options are acid and therefore furnish hydrogen ions when dissolved in water, making them strong acid.
And ammonia dissolves in water to form its conjugate ammonium ion and hydroxide ion, therefore making the solution basic.
Hence, from the given options, the correct option is E. [tex]NH_3[/tex]
The compound which when dissolved in water, forms a weak acid is; Choice E: NH3
According to the question;
we are required to determine which compound forms a weak acid when dissolved in water.Unlike other compounds (HNO3, HClO, HBr, HClO) which dissolve in water to yield H+ ion, Ammonia dissolves in water to form ammonium ion and hydroxide ion, OH-.
In essence, NH3 is a strong base when dissolved in water and consequently, is a weak acid when dissolved in water.
Read more:
https://brainly.com/question/15192126
You rub a comb on your hair and then the comb is able to pick up pieces of paper. Explain why this happens
Answer:
This happened because,the comb was charged with static electricity when it was rubbed on your hair.
(¬_¬)ﾉ( ˘ ³˘)♥
How did the industrial Revolution impact the population of peppered moths in Britain?
The Industrial Revolution caused the proportions of each color morph in the population to become equal.
The light-colored moths became more common
The dark-colored moths became more common
The Industrial Revolution caused the proportions of each color morph in the population to become unequal
Answer:
due to the pollution the light months tended to stand out against the the wood that was dark due to the smoke the darker months population grew due to the fact that they were more harder to see for the predators
Answer:
The dark colored months became more common
Explanation:
Thats the answer !
What do the symbols in the parentheses indicate
Answer:
(C) the physical state of each reactant and product
Explanation:
Hope this helps
How many grams are in 3.0 moles of sodium chloride (NaCl)?
Answer:
175.5
Explanation:
What is the percent yield of water from the combustion of propane (C3H8), if my theoretical yield is 8.17g of water and my actual yield was 6.13 g water?
A)Answer not shown
B)0.75%
C)75%
D)1.33%
Answer:
im not sure
Explanation:
i went on here looking nobody answered yet
Potential and kinetic energy are similar in that -
COME ON BESTIES I NEED HELP
Answer:
They refer to energy that moves. Kinetic energy is energy that is currently moving. Potential refers to energy that has yet to move, or simply energy in wait
Explanation:
Answer:
I'm not 100% but a possible answer could be: No energy could either be created or destroyed
LMK if not but good luck!
The trait that shows up in the first generation.
Recessive
Dominant
Ok
Answer:
Dominant
Explanation:
hope this help
How many protons are in nitrogen
Answer:
Explanation:
There are 7 protons in nitrogen
7 TYPE OF NITRONGEN
. . .
How many molecules of O2 will be formed from 0.500 grams of KCIO3
Answer:
3.7 x 10²¹ O₂ molecules
Explanation:
2KClO₃ => 2KCl + 3O₂
given 0.500g KClO₃ => 0.500g/122.55g/mol = 0.0041 mole KClO₃
0.0041 mole KClO₃ => 3/2(0.0041) mole O₂ = 0.0061 mole O₂
0.0061 mole O₂ = 0.0061 mole O₂ x 6.02 x 10²³ molecules O₂/mole O₂
= 3.7 x 10²¹ molecules O₂
HELP QUICK!!!!!!
How many valence electrons do the atoms in Group 13 have?
Answer:
The answer is 3 valance electrons.
Explanation:
Hope this helped Mark BRAINLIEST!!!
Answer:
3 valence electrons
Explanation:
The atoms in group 13 have three valence electrons.
Which equation is an example of a redox reaction?
A. Ca(OH)2 + H2SO3 + 2H20 + CaSO3
B. HCI + KOH + KCI + H20
C. 2K+ CaBr +2KBr + Ca
D. BaCl2 + Na2SO4 + 2NaCl + BaSO4
Answer:
The answer is C.
Explanation:
A P E X approved :)