Chemistry Answers

• Which element has atoms in the ground state with the greatest number of valence electrons?

“determine the concentration of an unknown Copper Sulphate Solution: by measuring its absorbance and using the slope of the Beer’s Law Curve”.

coal sample has the following composition by weight C =70 %, H

=10 %, O = 12%, S =5 %, N = 3 %. Calculate the gross and net calorific

value using Dulong’s formula.

The reaction 2 NO(g) = N2(g) + O2(g) has a Kc value of 2400 at 2000 K. If 0.850 M each of N2 and O2 are initially present in a 3.00-L vessel, calculate the equilibrium concentrations of No, N2 and O2.

The reaction 2 NO(g) = N2(g) + O2(g) has a Kc value of 2400 at 2000 K. If 0.850 M each of N2 and O2 are initially present in 3.00-L vessel , calculate the equilibrium concentrations of No, N2, and O2.

when 1.50 mol CO2 and 1.50 mol H2 are placed in a 3.00-L container at 395°C, the following reaction occurs: CO2(g) + H2(g) = CO(g) + H2O(g). If Kc = 0.802, what are the concentrations of each substance in the equilibrium mixture?

1. 5.00 g NaOH and 5.00 g Ba(OH)2 were used to prepare 1L solution each. Which solution will be more basic? (MM NaOH=40, Ba(OH)2=171.3)

2. You decide to test the pH of your brand new swimming pool. The instruction manual advises to keep it between 7.2-7.6. Shockingly, you found out that the pH of your pool is 8.3! What kind of chemical should you add?

B. Nitrous Oxide (N_{2}*O) commonly known as laughing gas, is easily oxidized to dinitrogen tetraoxide (N_{2}*O_{4}) . If the equilibrium concentrations of f N 2 O? , O_{2} and f*N_{2}*O_{4} are 0.089M, 0.064M, and 2.5M, respectively, what is the equilibrium constant k_{c} for the reaction?

2N 2 O (g) +3O 2(g) Leftrightarrow2N 2 O 4 8)

What mass of CuSO4(s) is present in 10.0 mL of the final dilute solution?  

10.3 moles of H2O are produced. How

many moles of Fe are also produced?