Physical Chemistry Answers

NH3+O2=NO+H2O IF 25G NH3 is reacted with 20g O2, which is the limiting reagent? How much NO will be formed in the reaction?

Calculate the standard enthalpy of formation per mole of ZnS(s).

ZnS(s) + O2(g) → ZnO(s) + SO2(g) ΔH = −878.2 kJ

ΔH_fo(ZnO(s)) = −348.3 kJ/mol

ΔH_fo (SO2(g)) = −296.8 kJ/mol

100 g of manganese dioxide reacts with 300 g of hydrochloric acid in the reaction shown below.

MnO2 + 4HCl -> MnCl2+ 2H2O + Cl2 

 (Use the following molar masses: MnO2= 86.9g/mol HCl = 36.5g/mol ; MnCl2= 125.8g/mol; H2O= 18.02g/mol and Cl 2 =70.9 g/mol.

 a. Which reactant is limiting?

b. Which reactant is excess? 

c. What is the theoretical yield of Cl2? 

d. What is the percent yield of the reaction if 75.0 g of Cl2 was produced

Draw the Lewis structures of the following ions giving all the steps.

(i) S2

2- (ii) OCl- (iii) CN

Two mole of an ideal gas is heated at a constant pressure of 101.3K Nm^-2 from 273.2 K to 373K. Calculate, in Joules, the work involved

A reaction is spontaneous when change in Gibb's energy is.....

The following statements are reasons why you cannot get the heat of formation from direct reaction between elements that for compounds except? 1.the reaction those not go into completion. 2.reaction is not complex. 3.the compounds obtained are not pure enough. 4.there are side reaction.

Calculate the 1) average speed, 2) root mean square speed and, 3) most probable speed of oxygen molecules at 515k. (Given Mm(O2)=0.016kgmol^-1).

How many valence electrons are found in this element with a configuration of 1s2 2s2 2p6 3s2 3p5?

The decomposition of acetaldehyde in gas phase was studied at 729k using the initial concentration of 7.77×10^-3M and 3.64×10^-3M. The half life periods were determined to be 295s and 515s respectively. Determine the order of the reaction.