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boyakko [2]
2 years ago
14

Can someone help, please...? I really can't understand this...

Chemistry
1 answer:
barxatty [35]2 years ago
5 0
It’s okay to be a little intimidated by this but the answer is a lot more simple than it may look. All you have to do is multiply the standard enthalpies of formation with their stoichiometric coefficient for every chemical and subtract the reactants from the products:

6(-393.5) + 3(-285.8) -1(49) -15(0)
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A sample of hydrated copper (II) sulfate (CuSO4•nH2O) is heated to 150°C and produces 103.74 g anhydrous copper (II) sulfate and
wariber [46]

Answer:

5

Explanation:

Firstly, we convert what we have to percentage compositions.

There are two parts in the molecule, the sulphate part and the water part.

The percentage compositions is as follows:

Sulphate- (103.74)/(103.74 + 58.55) × 100% = apprx 64%

The water part = 100 - 64 = 36%

Now, we divide the percentages by the molar masses.

For the CuSO4 molar mass is 64 + 32 + 4(16) = 160g/mol

For the H2O = 2(1) + 16 = 18g/mol

Now we divide the percentages by these masses

Sulphate = 64/160 = 0.4

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The absolute temperature of a gas is increased four times while maintaining a constant volume. What happens to the pressure of
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Answer:

DECREASE BY A FACTOR OF FOUR

Explanation:

Using pressure equation:

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P1 = P

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P2 = ?

T2 = 4 T

So therefore;

P2 = P1T1/ T2

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P2 = 1/4 P

The pressure is decreased by a factor of four, the new pressure is a quarter of the formal pressure of the gas.

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A gas mixture contains 0.800 mol of N2, 0.200 mol of H2, and 0.150 mol of CH4. What is the mole fraction of H2 in the mixture?
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Answer:

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0.800 mol of N2

0.200 mol of H2

0.150 mol of CH4

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4 0
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