posted by Hannah on .
1)A piece of metal with a mass of 5.50 grams changed in temperature from 25 to 55 degrees celsius when 21.3 joules was absorbed. What is the specific heat of the metal?
e)0.710 Jg^-1 C^-1
I chose 7.75 because I did 5.50/21.3 and then multiplied by 30.
2)Which of the following equations represents a reaction for which the delta H can be called a standard enthalpy of formation, delta Hf?
a) FeO(s) + CO2(g) -> FeCO3(s)
b) 1/2 N2(g) + 2 O(g) -> NO2(g)
c) 2 Na(s) + Cl2(g) -> 2 NaCl(s)
d) Ba(s) + N2(g) + 3 O2(g) -> Ba(NO3)2(s)
e) more than one of the four equations above are standard enthalpies of formation.
I chose answer e.
Are these correct?
21.3 = mass x sp.h. x delta T
sp.h. = 21.3/(5.50*30) is not 7.75.
I agree with d.
Ok for number one i got 0.129 and for number 2 did you mean that my answer choice of e was correct or that just equation d is correct? Thank you for your help!!