Sunday
April 20, 2014

Homework Help: Chemistry

Posted by Bobby on Wednesday, July 21, 2010 at 10:01pm.

1. The delta Hf of an element in its standard state is defined to be
a) 0 kJ/mol
b) 10 kJ/mol
c) -10 kJ/mol
d) greater than 0 kJ/mol
e) a unique value for each element

I am assuming its a?

2. Which of the following statements are true?
I) The reaction vessel cools when an endothermic reaction occurs.
II)An endothermic reaction has a negative value of delta H.
III)Heat is liberated when an exothermic reaction occurs.

a) I and II
b) I, II, and III
c) I and III only
d) II and III only
e) none of them

I am thinking that it's d?

3. Which factor does not affect the rate of a chemical reaction in aqueous solution?

a) The enthalpy change of the reaction
b) The activation energy of the reaction
c) The collision frequency of the reaction particles
d) The relative orientation of the colliding particles
e) The temperature of the solution.

It's a?

4. Which of the following processes are exothermic?
I) Boiling water
II) Freezing water
III) Condensing steam
IV) Melting ice

a) I and II only
b) II and III only
c) I and IV only
d) II, III, and IV only
e) II and IV only

it's b?

5. Which statement about an activate complex is true?
a) It is a stable substance
b) It has lower chemical potential energy, or enthalpy, than reactants or products.
c) It occurs only in endothermic reactions
d) It occurs at the transition state of the reaction
e) It always breaks down to form product molecules.

I am assuming it's d?

6. A catalyst changes the
I) Mechanism of a reaction
II) Enthalpy change of a reaction
III) Activation energy of a reaction

a) I only
b) III only
c) I and III only
d) II and III only
e) I, II, and III

I think it's b

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

AP Chem - The energy change H associated with the reaction NBr3(g) + 3H2O(g) -&...
ap chemistry - Carbon monoxide reacts with oxygen to form carbon dioxide by the...
Chemistry - 2CH3CH2CH2OH(l)+9O2(g)→6CO2(g)+8H2O(g) I have to find the ...
Chemistry - Predict whether the following reactions will be exothermic or ...
ap chem - calculate the lattice enthalpy of potassium fluoride from the ...
Chemistry - For a particular reaction at 195.1 C, ΔG = -1488.09 kJ/mol, ...
Chemistry - "Given that the bond enthalpy of the carbon-oxygen bonds in carbon ...
chemistry - A 79.9-L sample of a gaseous hydrocarbon, measured at 1.00 atm ...
Chemistry - C6H14 + 19/2 O2 -> 6 CO2 + 7H2O delta H = -4163 kJ What mass of ...
CHemistry Dr. Bob please? - for bond energies if tehy give u a diagram of the ...

Search
Members