The molar enthalpies of combustion of CH3COCOOH(l)CH3COOH(l) and CO(g) are respectively -1275kJ/mol, -875kJ/mol, and -283kJ/mol. What is the enthalpy change for the reaction below?

CH3COCOOH= CH3COOH+CO

a)1867kJ
b)-1867kJ
c)117kJ
d)-117kJ
e)-2433kJ

I think it's d)

Consider the following two thermochemical equations

N2+2.5O2-> N2O5(s) Delta H=xkJ
N2+2.5O2-> N2O5(g) Delta H=xkJ

The enthalpy change in kJ for the sublimation of one mole of N205 solid to gas would be represented by the quantity
a)x+y
b)x-y
c)y-x
d)-x-y

Assuming it's a)

What is the overall order of reaction for the elementary system A+2B=products?
a)0
b)1
c)2
d)3
e)5

I don't understand this question

When zinc, iron and lead are reacted with hydrochloric acid the variable most easily measured in order to determine the effect of the chemical nature of the reactants on reaction rate is

a)temperature
b)colour
c)surface area
d)volume of gas
e)concentration

Think it's d

What would the units of the rate constant k be in a second order equation if rate was measured in mol/(L x s)and all concentrations in mol/L

a)L/(mol x s)
b)L2/(mol2 x s)
c)L3/(mol3 x s)
d)mol2/(L2 x s)

I think it's b) but d) is very tempting

Can somebody approve my answers.

1 answer

You need to post just one question to a post. These long questions take too much time to answer and many volunteers have some time here and there so we can take care of small problems easier than large ones (or many problems).
For your first one, check your math. I didn't get that. For your second one you made a typo; both delta H values are listed as x kJ/mol.