Chemistry Answers

1. A semipermeable membrane allows

A. Only solute particles through

B. Only solvent particles through

C. Neither solute nor solvent particles

D. Both solute and solvent particles through

2. When you place a straw into a glass of water, the water seems to climb up the straw before you even place your mouth on the straw. Which property of water is related to this phenomenon? *

A. Water has high specific heat.

B. Water has a high heat of vaporization.

C. Water is a liquid at normal physiological temperature.

D. Water molecules are adhesive; they form H-bonds with polar surfaces.

3. Which statement is true about catalysts? *

A. They speed up the reaction.

B. They are unrecovered at the end of the reaction.

C. The amount of catalysts decreases as the reaction continues.

D. They can slow down the reaction by consuming the reactants.

Calculate the number of chloride ions in 200 cm cube of 0.5 mol magnesium chloride solution

. Calculate HCV and LCV of a fuel, whose composition by mass is as follows;

Carbon – 90%, Hydrogen – 90%, Sulphur – 90% and reminder being Ash

At a certain speed, the root-mean-square-speed of the molecules of hydrogen in a sample 

of gas is 1055 ms-1

. Compute the root-mean square speed of molecules of oxygen at the 

same temperature.

C6H12O6 +6O2 --> 6CO2 +H2O

If 54.1 grams of CO₂ is produced in the reaction above, how many grams of H₂O are produced in this reaction?

How many grams of oxygen are produced in the decomposition of 45.3g of potassium chlorate (KClO₃)?

A chemist encounters an unknown metal. They drop the metal into a graduated cylinder containing water, and find the volume change is 5.3 mL. If the metal weighs 6.8 g, what is the density of the metal in g/mL?