Other Chemistry Answers

The equation for the decomposition of mercury(II) oxide is as follows. Determine Heat of formation for HgO(s)?

2HgO(s)+182KJ=2Hg(l)+O2(g)

A sample of helium gas takes up 15 L. After being compressed down to a volume of 8 L, the sample has a pressure of 4.3 atm. What was the original pressure? 

3)

According to the following equilibrium:

Cr2O7^2-(aq) + H20(l) ⇌ 2CrO4^2- (aq) + 2H^+ (aq)

orange                yellow

Explain why a solution containing the following equilibrium system turns yellow when

sodium hydroxide is added.

I need help with this

For the reaction:

PCl3(g) + Cl2(g) ⇌ PCl5(g) H = -92.5 kJ

State:

 i) the direction of shift and ii) effect on [PC13] if the following changes are made:

i) temperature goes up

ii) chlorine is added

iii) volume drops

iv) a catalyst is added

I need help with this

From the following enthalpy changes,

C(s)  + O2(g) 🡪 CO2(g) ΔH  =  -393.5 kJ

H2(g)    +  ½ O2(g) 🡪 H2O(l) ΔH = -285.8 kJ 

CH4(g)    +   2O2(g)  🡪 CO2(g)  +  2H2O(l) ΔH  =  -890.3 kJ

calculate the value of ∆Hf for CH4. (3 marks for showing how to get to the overall reaction, stating the overall reaction  since  it  isn’t  given, and the heat of reaction)

1. From the following enthalpy changes, calculate the value of ∆H° for the reactions:

Xe (g) + F2  (g) 🡪 XeF2 (s) ∆H° = -123  kJ

Xe (g) + 2F2  (g) 🡪 XeF4 (s) ∆H° = -262 kJ

XeF2 (s) + F2 (g) 🡪 XeF4 (s)

Write the heat of formation reactions for the following compounds. Include the energy value and state whether the reaction is endothermic or exothermic.

1. FeO

1. KOH

1. NH4NO3

This question is related to the equilibrium reaction below:

H₂(g) + F₂(g) ⇌ 2HF (g),ΔH = -542 kJmol^-1

i. The following stresses are applied to the equilibrium:

1. the temperature is increased,

2. a catalyst is added,

3. the concentration of HF is reduced,

4. the volume is decreased.

Write the equilibrium expressions for K_c and K_p for each of the following reactions:

i. H₂(g) + F₂(g) ⇌ 2HF (g)

ii. Zn(s) + 2HCl(aq) ⇌ ZnCl₂(aq) + H₂(g)

Differentiate between static and dynamic equilibria.