Question

7.15g of Na2CO3.xH2O is dissolved in 250cm^3 of distilled water to form 0.10mol/dm^3. The entire solution was reacted with HCL to produce NaCl, H2O, and 8960cm^3 of CO2 gas at STP in a beaker. Calculate the concentration of Na2CO3.xH2O in g/dm^3 (molar mass of Na2CO3.xH2O).

a) 71.5 g/dm^3
b) 143 g/dm^3
c) 35.75 g/dm^3
d) 50.9 g/dm^3

Answer 1

To calculate the concentration of Na2CO3.xH2O in g/dm^3, convert the given information to moles and use the balanced chemical equation. The concentration of Na2CO3.xH2O is 71.5 g/dm^3 (Option a).

Step-by-step explanation:

To calculate the concentration of Na2CO3.xH2O in g/dm^3, we need to convert the given information to moles and use the balanced chemical equation of the reaction between Na2CO3.xH2O and HCl.

Given: 7.15g of Na2CO3.xH2O, 250cm^3 of distilled water to form 0.10mol/dm^3, and 8960cm^3 of CO2 gas at STP.

The molar mass of Na2CO3.xH2O can be calculated by using the molar masses of Na, C, O, and H, and then multiplying by the number of each element in the compound.

By using the molar mass of Na2CO3.xH2O and the number of moles of Na2CO3.xH2O, we can calculate the concentration of Na2CO3.xH2O in g/dm^3.

The concentration of Na2CO3.xH2O is 71.5 g/dm^3 (Option a).