Blackboard chalk contains a certain percentage of calcium carbonate. If a 1.51 g piece of chalk produces 0.665 g of carbon dioxide, what percentage of calcium carbonate is chalk?

The percentage of Calcium carbonate in chalk = 100%

Given

1.51 g piece of chalk produces 0.665 g of carbon dioxide

Required

percentage of calcium carbonate

Solution

Reaction

CaCO3 (s) + 2 HCl (aq) → CaCl2 (aq) + H2O (l) + CO2 (g)

mol CO2 :

= 0.665 g : 44 g/mol

= 0.015

From the equation, mol CaCO3 = mol CO2 = 0.015

mass CaCO3 :

= mol x MW

= 0.015 x 100

= 1.5 g

a pan containing water is placed in a positio n where it is exposed to a 10 mile per hour wind. the pan contains a uniform depth of 1.27 cm of water, is quite wide, and has a length of 2.44 m in the wind direction. the water in the pan is at a constant temperature of 15.5 °c.

i think its 5049.

i hope this !