General Chemistry Answers

A gas sample has a volume of 875 mL at 37^oC . What will the volume be at standard temperature?

Percentage purity of KOH in 6.50gdm

There is 5 grams of C^2H^6 in a combustion reaction , how many grams of each product is produced

 It is not safe to put aerosol canisters in a campfire, because the pressure inside the canisters gets very high and they explode. If Cindy has a 1.0 L canister that holds 2 moles of gas, and the campfire temperature is 1400°C, what is the pressure of the canister in kPa? 

2. 

PbF2(s)  ⇌ Pb2+(aq) + 2 F-(aq)

At a constant temperature, in a saturated solution of PbF2 the concentration of Pb2+ is 2.0x10-3 M. The equilibrium is represented by the equation above.

a.   Write the expression for the solubility-product constant, Ksp (2pt)

b.   Calculate the value of Ksp at this temperature. (3pt)

c.   You have a 1.00 L saturated solution of PbF2 and 0.0428 moles of solid NaF is added and dissolves completely. Calculate the equilibrium concentration of Pb2+ under these conditions and assume no change in volume occurred. (2pt)

d.   Is the concentration of Pb2+ in part (c) greater, less than, or equal to the original concentration. Explain why this is the case. (2pt)

1.       For the system, 2 CO2(g) ⇌ 2 CO (g) + O2 (g), the reaction is endothermic. Assume that a scientist has an equilibrium mixture of these substances. 

a. If oxygen was removed from the equilibrium mixture, (i) what would happen to the number of moles of CO present at equilibrium and (ii) what would happen to the value of the equilibrium constant?

b. If the temperature of the system were decreased, (i) what would happen to the number of moles of CO present at equilibrium and (ii) what would happen to the value of the equilibrium constant?

What is the molarity of the diluted solution when each of the following solutions is diluted to the given final volume?

0.5850 L of a 0.1110 M solution of Fe(NO₃)₃ is diluted to a final volume of 1.357 L.

1. The empirical formula of hydrocarbon is C2 H3 .The hydrocarbon has a relative molecular mass of 54 calc molecular formula of hydrocarbon

The standardized Na2S2O3 titrant is then used to determine the amount of hypochlorite in a 5.0 grams commercial bleach sample via reduction with potassium iodide in acidic medium as shown in the succeeding equations.

(A) If 77.5 milliliters of the Na2S2O3 titrant is required to reach the starch endpoint for the bleach sample while 2.25 milliliter of the titrant is needed for the blank analysis, what is the percent NaOCl in the commercial bleach? Write answer in THREE SIGNIFICANT FIGURES. Write the full computation of your solution.

For hypochlorite determination in bleach samples, the substance of interest is measured by titration with sodium thiosulfate (na2s2o3). the titrant is first standardized using 0.1075 gram potassium iodate (kio3) in an acidic solution requiring 30.25 ml of sodium thiosulfate titrant. the standardization follows the reactions given below.

(A) Calculate the standardized molar concentration of sodium thiosulfate, Na2S2O3? Write answer in THREE SIGNIFICANT FIGURES. Write the full computation of your solution.