General Chemistry Answers

A sample of CH₄ is burned in an excess of O₂ to give 777 moles of H₂O. How many moles of CH₄ were in the original sample?

The equilibrium constant for the formation of Cu(CN)42- is 2.0 x 1030. Calculate the value of pCu2+, i.e. -log[Cu2+], if 2.48 g of CuCl2 is dissolved in 1.000 L of a 0.937 M NaCN solution. The addition of CuCl2 does not affect the volume (the final volume is always 1.000 L).

The solubility product of Cu(OH)2 is 4.8 x 10-20. Calculate the value of pCu2+, i.e., -log[Cu2+], in an aqueous NaOH solution that has a pH of 12.44 and is saturated with Cu(OH)2.

Watch the following video (up until 21:20) https://youtu.be/311baBOQARQ 

then answer the following: 

✶ What are 3 important things learned from this lesson?

Arturo is supposed to weigh 135.5 g of his protein whey for his early morning power shake. However, the analytical balance shows that the protein whey he scooped is 148.93 g. How much is the excess protein whey that Arturo weighed? Express your final answer with a correct number of significant figures. 

Aleck measured the air temperature every morning for five consecutive days. She obtained the following readings: 31.2 0C, 30.8 0C, 31.0 0C, 29.8 0C, 31.3 0C. What is the average air temperature every morning? Express your final answer with a correct number of significant figures. 

Nitroglycerine, C3H5(NO3)3(l), a powerful explosive used in

mining, detonates to produce a hot gaseous mixture of nitrogen,

water, carbon dioxide, and oxygen.

(a) Write a balanced equation for this reaction using the smallest

whole-number coefficients.

(b) If H°rxn  2.29 104 kJ for the equation as written in

part (a), calculate H°f of nitroglycerine.

CO2

H2O(l)

C6H12O6(s)

O2(g)

∆H (kJ/mol)

-393.5

-285.8

-1273.3

S° (J/mol ∙ K)

213.6

69.9

209.2

205.0

Instruction: Calculate the ∆H°, ∆S°, and ∆G°. Is the reaction spontaneous at standard condition?

Calculate the pressure of hydrogen gas produced if 50 grams of Aluminum

reacts with 250 grams of Hydrochloric acid. The Hydrogen gas is collected

at 2.75 L vessel at 80.6 ℉.

How much Cl2 in grams is required to produce 12.0g CCl4