The general trend for a substance's heat capacity and atomic mass is that they are inversely proportional. This is because denser or larger atoms have particles that are closer to each other. The close proximity of these particles make it easier to transfer heat because of their increased vibration, making the heat capacity required smaller.
Answer:
3,116J/K
Explanation:
This question asks to calculate the entropy change of the surroundings.
To do this, we need the standard enthalpy of formation ΔfH° of the reacting species and products first:
We should observe that standard enthalpy if formation of O2 is zero. We proceed with the rest of the species.
H2CO = -109.5KJ/mol
CO2 = -393.5KJ/mol
H2O = -285.8KJ/mol
Now, we calculate the standard change of enthalpy of the reaction as:
ΔHrxn = ΔHproduct - ΔHreactant = (-285.8 - 393.5) +(109.5) = -569.8 KJ/mol
The relationship between the entropy and the standard formation enthalpy is given as
The relationship is:
ΔSosurroundings = - ( ΔHof/ T)
We convert the standard enthalpy of formation to joules first = -569.8 * 10^3 Joules
Using the formula above at a temperature of 298k, the entropy change would be:
-(-569.8 * 10^3)/298 = 1912J/K
Now, we know that 1.63 moles of H2CO reacted. We also need to know the coefficient of the H2CO in the reaction which is 1.
We thus have:
1.63 mol H2CO(g) * (1912J/K * 1 mol H2CO) = 3116J/K
Answer:
leading zeroes to the left of a decimal point. and trailing zeros to the left of an invisible decimal point.
Explanation:
- All nonzero digits are significant figures. Example: 713 has three significant figures. 18,991 has five significant figures.
- Zeros located between two nonzero digits are significant figures. Example: 505 has three significant figures. 17,009 has five significant figures.
- Zeros at the ends of numbers are only significant if there is a decimal point in the number. Example: 502.00 has five significant figures (5,0,2,0,0). 5020 has three significant figures (5,0,2) 100,000 has one significant figure (1)
- Zeros that come before the first nonzero digit are not significant. Example: 0.0007 has one significant figure (7). 0.0970 has three significant figures (9,7,0)
B because isotopes have the same number of protons but a different number of neutrons
