What is the percent composition of hydrogen in a compound if the mass of the initial compound is 276 grams and the mass of collected hydrogen after decomposition is 41.4 grams?

A.

6.6%

B.

10.0%

C.

15.0%

D.

21.2%

A solute with a density of 1.15 g/mL and mass of 45.95 g is dissolved in 250. mL of water. What is the volume of the solute, and what is the volume percent (v/v) ?

A plastic bottle is closed outdoors on a cold day when the temperature is - 15.0°C and is later brought inside where the temperature is 21.5°C.

A fellow student does not understand why air is a mixture. Write a brief explanation about why air is a mixture, whether it is homogeneous or heterogeneous, and how it can be separated.

An experiment requires 40.0g of ethylene glycol, a liquid whose density is 1.114 g/mL. Rather than weigh the sample on a balance, a chemist chooses to dispense the liquid using a graduated cylinder. What volume of the liquid should he use?

How many calories are released when 500 g of water cools from 95.0°C to 25.0°C?

A solution which has a concentration that exceeds its predicted solubility at a certain temperature and pressure would be -

Convert 4.992*1010 g to each of the following units. B. Mg c. mg D. metric tons

The ideal gas law shows us how a gas will behave under many conditions. The formula is: P V = n R T Where P = pressure, V = volume, n = amount of the substance, R = ideal gas constant, and T = temperature.

The Suns ultraviolent Rays can cause skin damage including sunburn and even skin

Peas contain 250 kJ per 100 g. You would use the equivalent of 600 g of peas if you slept for.