if the freezing point of a substance is 68°C, what is its melting point?

Answer:

they meen like what youve learned or like what youve been tonight....all that is work stuff you did for example school work.

Answer:

Yes because magnesium has a more negative reduction potential than aluminum.

Explanation:

The single factor that will determine whether a battery with magnesium as anode and aluminium as cathode will work or not is the respective electrode potentials of the two elements.

Recall that in a battery, oxidation occur at the anode and reduction occurs that the cathode. The reduction potential shows the ease with which a metal is reduced or oxidized. The substance with the most negative reduction potential will function as the anode while the substance with the less negative electrode potential will function as the anode.

The reduction potential of Magnesium is -2.37 V while that of aluminum is -1.66 V. This implies that magnesium must function as the anode and aluminum as the cathode in order to have a spontaneous electrochemical process in the cell.

Answer:

0.472 grams of aluminum oxide would be produced from the reaction of 0.25 grams of aluminum with excess oxygen gas.

Explanation:

First of all, you should know that the balanced reaction that occurs:

4 Al + 3 O₂ → 2 Al₂O₃

Then, by stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts are produced in moles:

Being:

The molar mass of the compounds participating in the reaction is:

Then, by stoichiometry of the reaction, the following amounts of mass react and are produced:

Now it is possible to apply the following rule of three: if 108 grams of Al produce 204 grams of Al₂O₃, 0.25 grams of aluminum how much mass of Al₂O₃ will it produce?

[tex]mass of Al_{2} O_{3} =\frac{0.25 grams of Al*204 grams of Al_{2} O_{3} }{108 grams of Al}[/tex]

mass of Al₂O₃=0.472 grams

0.472 grams of aluminum oxide would be produced from the reaction of 0.25 grams of aluminum with excess oxygen gas.

Answer:

D

Explanation:

Answer:

Rubidium 265 pm

Explanation:

As can be seen in the figures below, the atomic radius increases from top to bottom in a group, and decreases from left to right across a period

Hydrogen 53 pm

Lithium 167 pm

Sodium 190 pm

Answer:

98.6%

Explanation:

First we put down the equation representing the decomposition of sodium bicarbonate.

2NaHCO3(s) ----> Na2CO3(s) + H2O(l) + CO2(g)

We can see from the data provided that the mass of sodium bicarbonate reacted is 3.01 g.

The number of moles of sodium bicarbonate reacted= mass of sodium bicarbonate/ molar mass of sodium bicarbonate

Molar mass of sodium bicarbonate= 84.007 g/mol

Number of moles of sodium bicarbonate=3.01 g/ 84.007 g/mol

Number of moles of sodium bicarbonate= 0.0358 moles

From the balanced reaction equation,

2 moles of sodium bicarbonate yields 1 mole of sodium carbonate

Hence 0.0358 moles of sodium bicarbonate yields 0.0358/2 = 0.0179 moles of sodium carbonate

Theoretical yield of sodium carbonate = number of moles of sodium carbonate × molar mass of sodium carbonate

Molar mass of sodium carbonate= 105.9888 g/mol

Theoretical yield of sodium carbonate= 0.0179 moles × 105.9888 g/mol

Theoretical yield of sodium carbonate= 1.897 g

Actual yield of sodium carbonate= 1.87 g

%yield of sodium carbonate= 1.87/1.897 ×100

%yield of sodium carbonate= 98.6%

Answer:

3C + 2Fe ₂ O ₃ → 3CO ₂ + 4Fe

Explanation:

C + Fe ₂ O ₃ → CO ₂ + Fe

Left Side

C = 1

Fe = 2

O = 3

Right Side

C = 1

Fe = 1

O = 2

So we can see that while Carbon is balanced Fe and O are not.

We then attempt to balance the equation by balancing the Oxygen.

C + 2Fe ₂ O ₃ → 3CO ₂ + Fe

Left Side

C = 1

Fe = 4

O = 6

Right Side

C = 3

Fe = 1

O = 6

Oxygen is now balanced but C and Fe are not, though this is an easy fix as each are independent on each side of the equation.

3C + 2Fe ₂ O ₃ → 3CO ₂ + 4Fe

Left Side

C = 3

Fe = 4

O = 6

Right Side

C = 3

Fe = 4

O = 6

Answer:

2 , 3 , 4 , 3

Explanation:

Answer:

11grams

Explanation:

Use the law '' conversation of mass ''

Because the sugar dissolved in water.

Cheers! :D

PS: Mark me as brianest. Thx.

Answer: 2.5 moles

2H2 + O2 = 2H2O

This implies that 2 moles of oxygen is needed to react with one mole of oxygen to form 2 moles of water

It also implies that

2 moles of hydrogen requires 32 grams of oxygen

? moles of hydrogen would require 40 g of oxygen

2 x 40/32 = 2.5 moles

Answer: nucleus

Explanation: the bigger the nucleus there more reactive the atom is

Answer:

The larger an atom is, the more reactive it will be.

It helps to think about the size of an atom with the location of the electrons and nucleus in mind. You know that protons are positively charged and electrons are negatively charged, therefore there is a level of attraction between these two oppositely charged subatomic particles. This attraction helps stabilize the atom.

Now, in a larger atom, with more electrons are those electrons (specifically the valence electrons) going to be closer or further from the nucleus than in a smaller atom?

They will of course be further from the nucleus and therefore further from the positively charged nucleus. This makes it easier for the valence electrons to leave the atom and form an ionic bond or to interact with another atom to form a covalent bond.

If electrons can leave more easily, then the atom is more likely to react.

Answer:

A

Explanation:

Hmm, so we have the following in the diagram

Pt(s)

Cl2(g)

Ag(s)

NaCl(aq)

AgNO3(aq)

Pt 2+, 4+, 6+  Though it states Pt is inert

Cl 2-

Ag 1+

Na 1+

NO3-

Anode definition: the positively charged electrode by which the electrons leave an electrical device.

Electrode definition: a conductor through which electricity enters or leaves an object, substance, or region.

Cations attracted to cathode pick up electrons

Anions attracted to anode release electrodes+

Reduction at Cathode (red cat gain of e)

Oxidation at Anode (ox anode loss of e)

So from the diagram we can see that the charge is being generated through the 2 metal plates.

So the answer is A, the anode material is Pt and the half reaction is 2Cl- = Cl2 + 2e-

Answer:

Solid

Explanation:

Solid has a definite shape and its molecules have high density.

Hope this will help you.

Answer:

B. 225 W

Explanation:

Power is the measure of the amount of work done in a certain time frame. It can be found using the following formula.

p=w/t

where w is the amount of work done in joules and t is the amount of time in seconds.

We know that 900 joules of work was done in 4 seconds.

w=900 J

t= 4 s

Substitute these values into the formula.

p=900 J/ 4 s

Divide 900 by 4

900/4=225

p= 225 J/s

1 Joules of work per second (J/s) is equal to 1 Watt (W). Therefore, we can substitute Watts for Joules per second.

p= 225 Watts

The power is 225 Watts, and the correct answer is B.

Answer:

If the reaction is going from left to right it would be synthesis, if going right to left it would be decomposition.

Explanation:

Na2O (s) + 2CO2 (g) + H2O (g) = 2 NaHCO3 (s)

Left Side

Na = 2

O = 6

C = 2

H = 2

Right Side

Na = 2

O = 6

C = 2

H = 2

Ok so is balanced already, though initial equation in question had an error in regards to the left hand side the ) should have been an O.

Hmm

Na2O (s) + 2CO2 (g) + H2O (g) = 2 NaHCO3 (s)

If it was going from right to left would be decomposition

But going from left to right it would be synthesis

Answer:

An increase in the amount of CO2 well increase the rate of photosynthesis, Carbon dioxide concentration will directly affect the rate of photosynthesis as it is used in the photosynthesis reaction.Increased amount of CO2 will increase the rate of photosynthesis to a certain limit, after which a further increase in its amount will no longer increase the rate any further.

Hope this helps.

Cheers! :)

Answer:C is not the answer. I just got it wrong in Edmentum

Explanation:

Answer:

no

Explanation:

Homogeneous means that the substance looks uniform throughout. This means that all of it looks the same (ex. juice or water). Because you can see the different parts of raisin bran cereal with milk it is not homogeneous, it is heterogeneous.

Answer:

22.6881 Grams of CO

Explanation:

Fe2O3 + 3CO = 3CO2 + 2Fe

Ratio

1:3 = 3:2

How many grams of CO are needed to produce 30.2 grams of Fe

Fe2O3 Molar mass: 159.69 g/mol

CO Molar mass: 28.01 g/mol

Fe Atomic mass: 55.845

Ok so our end result is 30.2 Grams of Fe, we have 2 Fe so we have 15.1 Grams per Fe

15.1/55.845 = 0.27

So then we multiply this by 3 as we we know the ratio and get get 0.81 required as this is 3CO.

So we need 0.81 Moles of CO so we need 22.6881 Grams of CO.

Answer:

C

Explanation:All the other answers are wrong

Answer:

it causes alot of harm to the earth.

Explanation:

earthquakes

an so on

Answer:

“The answer to this question” is more general. The preposition to denotes assignment - that the answer is being “applied” to the question, whether the answer is right or wrong. Conceptually, that makes a lot more sense than the previous one. This is also the more common usage.

Answer:

0.019 L or 19.1 mL

Explanation:

Given the equation of the reaction; we have:

CaBr2 + 2AgNO3 --> Ca(No3)2 + 2AgBr

We must first obtain the number of moles of AgNO3 reacted. This can be obtained from;

Concentration of AgNO3 reacted= 0.115 M

Volume of AgNO3 reacted= 50 ml

Since

Number of moles of AgNO3= concentration of AgNO3 × volume of AgNO3

Number of moles = 0.115 M × 50/1000 = 5.75 ×10^-3 moles

From the reaction equation;

2 moles of AgNO3 reacts with 1 mole of CaBr2

5.75 ×10^-3 moles of AgNO3 reacts with 5.75 ×10^-3 moles × 1 /2 = 2.875×10^-3 moles of CaBr2

Now;

Number of moles of CaBr2= concentration of CaBr2 × volume of CaBr2

Number of moles of CaBr2= 2.875×10^-3 moles

Volume of CaBr2= ????

Concentration of CaBr2= 0.150 M

Hence;

Volume of CaBr2= number of moles of CaBr2/ concentration of CaBr2

Volume of CaBr2= 2.875×10^-3 moles / 0.150

Volume of CaBr2= 0.019 L or 19.1 mL

Answer:

19 mL of CaBr₂ solution should be used to react with AgNO₃

Explanation:

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction) react:

50 ml of 0.115 M AgNO₃ react. Since molarity is the number of moles of solute per liter of solution, then you can do the following rule of three: if there are 0.115 moles of AgNO₃ in 1 L, in 0.05 L (being 1 L = 1000 mL, then 50 mL = 0.05 L How many moles are there?

[tex]moles of AgNO_{3}=\frac{0.05L*0.115 moles}{1 L}[/tex]

moles of AgNO₃=5.75*10⁻³

Now we can make a new rule of three to calculate the amount of moles necessary for CaBr₂ to react with moles of AgNO₂: if stoichiometry 2 moles of AgNO₃ react with 1 mole of CaBr₂, 5.75*10⁻³ moles of AgNO₃ with how many moles of CaBr₂ react ?

[tex]moles of CaBr_{2} =\frac{5.75*10^{-3}moles of AgNO_{3}*1 mole of CaBr_{2} }{2moles of AgNO_{3}}[/tex]

moles of CaBr₂=2.875*10⁻³ moles

Being 0.150 the molarity of the CaBr₂ compound, you can apply the following rule of three: if by definition of molarity 0.150 moles are in 1 L, 2.875 * 10⁻³ moles in how much volume is it present?

[tex]volume=\frac{2.875*10^{-3} moles*1L}{0.150 moles}[/tex]

volume=0.019 L

Being 1 L = 1000 mL, then 0.019 L = 19 mL

19 mL of CaBr₂ solution should be used to react with AgNO₃

Answer:

limited resources

Explanation:

nonrenewable resources are those resources found inside the earth that are in a fixed amount. They are being used at a faster rate, and cannot be renewed. These resources include fossil fuels,natural gas, and coal.

// have a great day //

Answer:

The HWA attacks eastern hemlock trees in forests and ornamental hemlock trees found in our residential landscaping. It feeds on the hemlock trees' young twigs by sucking the sap, causing their buds to die and needles to dry out and drop from the plant prematurely i think

hope i helped!!

Answer:

copper(ll) carbonate

Explanation:

Since the product is a salt which is copper(II) carbonate, water and carbon dioxide, this reaction is an acid + metal carbonate reaction.

Looking at the salt, Cu²⁺ has to be part of the reactants.

Hence, the missing compound there has to be copper(ll) carbonate, CuCO₃.

The balanced chemical equation would be:

CuCO₃ + 2HNO₃➙ Cu(NO₃)₂ +H₂O +CO₂

P.s. You left out CO₂ as a product in Q2 ;)

Just a recap of the main reactions you would've learnt:

1) Acid + base/ alkali ➙ salt + water

2) Acid + metal ➙ salt + hydrogen gas

3) Acid + metal carbonate ➙ salt + H₂O + CO₂

Answer:

C

Explanation:

Oxygen & water form rust