Amixture contained calcium carbonate and magnesium carbonate in unspecified proportions. a 7.85g sample of this mixture has reacted with excess hydrochloric acid, producing 1.94l of carbon dioxide at 25 degrees c and 785mmhg. what are the percentage of calcium carbonate and magnesium carbonate in the sample?

The percentage of calcium carbonate is 76.3% and magnesium carbonate is 23.7%.

Explanation:

produced ca be calculated from ideal gas equation:

P= Pressure of the gas = 785 mmHg = 1.03 atm    (760 mmHg= 1 atm)

V= Volume of the gas = 1.94 L

T= Temperature of the gas = 25°C=(25+273)K= 298 K   (0°C = 273 K)

R= Value of gas constant = 0.0821 Latm\K mol

Mass of

If the mass of calcium carbonate is x g , (7.85-x) g of magnesium carbonate is there.

As, 100 g of react to give 44 g of gas

So, x g of react to give of gas

The balanced chemical reaction will be:

As, 84 g of react to give 44 g of gas

So, of react to give of gas

By solving the terms, we get the value of x

x = 5.99 g

The mass of = x = 5.99 g

The mass of = 7.85 - 5.99 = 1.86 g

Now we have to calculate the percentage of magnesium carbonate.

Therefore, the percentage of calcium carbonate is 76.3% and magnesium carbonate is 23.7%.

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.