Answer:
Explanation:
Entropy change in the system : --
ΔG = −54 kJ⋅mol−1 (−13 kcal⋅mol−1) = −54 kJ⋅mol−1 (−13 x 4.2 kJ⋅mol−1)
= - 108.6 KJ / mol
ΔH = -251 kJ/mol (-60 kcal/mol) = -251 kJ/mol (-60 x 4.2 kJ/mol)
= - 503 KJ / mol
ΔG = ΔH - TΔS
ΔS = ( ΔH - ΔG ) / T
= - 503 + 108.6 / ( 273 + 25 ) KJ / mol k⁻¹
= - 1323.48 J / mol k⁻¹
Entropy change in the surrounding
+ 1323.48 J / mol k⁻¹
Answer:-
0.91% is the students % of error
Explanation: -
Accepted value= 12.11 grams
Measured value = 12.22 grams
Error = 12.22-12.11 = 0.11 grams
Percentage error =
x100
= 0.91 %
Thus 0.91% is the students % of error
Mass of lead (II) chromate is 51 g. The molecular formula is
and its molar mass is 323.2 g/mol
Number of moles can be calculated using the following formula:

Here, m is mass and M is molar mass.
Putting the values,

Therefore, number of moles of lead (II) chromate will be 0.1578 mol.
Answer: 
Explanation:
Significant figures : The figures in a number which express the value or the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
Rules for significant figures:
Digits from 1 to 9 are always significant and have infinite number of significant figures.
All non-zero numbers are always significant.
All zero’s between integers are always significant.
All zero’s after the decimal point are always significant.
All zero’s preceding the first integers are never significant.
Thus
has three significant figures