When a 1.25-gram sample of limestone was dissolved in acid, 0.44 gram of co2 was generated. if the rock contained no carbonate other than caco3 , what was the percent of caco3 by mass in the limestone?

80%

Explanation:

First off, we write out the chemical equation for the reaction, assuming the acid used is HCl;

CaCO3 + 2 HCl → CaCl2 + H2O + CO2

1 mol of CaCO3 generates 1 mol of CO2

Molar mass of CaCO3 = 40 + 12 + (3 * 16) = 52 + 48 = 100 g/mol

Molar mass of CO2 =12 + (2*16) = 12 + 32 = 44 g/mol

So mass of CaCO3 = 1 mol * 100 g/mol = 100 g

Mass of CO2 formed = 1 mol * 44 g/mol = 44 g

This means 100g of CaCO3 generated 44g of CO2

How much would then generate 0.44g?

100 = 44

x = 0.44

Upon cross Multiplication we have;

x = (0.44 * 100) / 44

x = 1g

Percent by mass of CaCO3 =  (mass of CaCO3 / Mass of Limestone) * 100

Percent by mass of CaCO3 = (1 / 1.25) * 100 = 0.8 * 100 = 80%

in chemistry, adhesion and cohesion are attractive forces that exist between molecules. they hold the molecules together from each other. they are different in that adhesive force exists between molecules of different substance while cohesive force happens between molecules of same substance.

adhesion between water and glass causes water molecules at the edge of water and glass interface to climb up the wall in a narrow glass tube. this is called capillary action. cohesion is what gives glass its shape and causes water to form a droplet.