Oxalic acid can remove rust (Fe2O3) caused by bathtub rings according to the reaction Fe2O3(s) - 6H2C2O4(aq) rightarrow 2Fe(C2O4)33-(aq) - 3H2O(l) - 6H+(aq) C calculate the number of grams of rust that can be removed by 6.00 times 102 mL of a 0.100 M solution of oxalic acid.

The mass of rust that can be removed is 1.597 grams

Explanation:

To calculate the number of moles for given molarity, we use the equation:

    .....(1)

Molarity of oxalic acid solution = 0.1255 M

Volume of solution = = 600 mL = 0.600 L    (Conversion factor:  1 L = 1000 mL)

Putting values in equation 1, we get:

For the given chemical reaction:

By Stoichiometry of the reaction:

6 moles of oxalic acid reacts with 1 mole of ferric oxide (rust)

So, 0.06 moles of oxalic acid will react with = of ferric oxide (rust)

To calculate the mass of rust for given number of moles, we use the equation:

Molar mass of rust (ferric oxide) = 159.7 g/mol

Moles of rust = 0.01 moles

Putting values in above equation, we get:

Hence, the mass of rust that can be removed is 1.597 grams

74.81 grams of calcium carbonate are produced from 79.3 g of sodium carbonate.

Explanation:

The balanced reaction is:

Na₂CO₃ + Ca(NO₃)₂ ⟶ CaCO₃ + 2 NaNO₃

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:

Na₂CO₃: 1 mole Ca(NO₃)₂: 1 mole CaCO₃: 1 mole NaNO₃: 2 mole

Being the molar mass of the compounds:

Na₂CO₃: 106 g/moleCa(NO₃)₂: 164 g/mole  CaCO₃: 100 g/mole NaNO₃: 85 g/mole

then by stoichiometry the following quantities of mass participate in the reaction:

Na₂CO₃: 1 mole* 106 g/mole= 106 gCa(NO₃)₂: 1 mole* 164 g/mole= 164 g CaCO₃: 1 mole* 100 g/mole= 100 gNaNO₃: 2 mole* 85 g/mole= 170 g

You can apply the following rule of three: if by stoichiometry 106 grams of Na₂CO₃ produce 100 grams of  CaCO₃, 79.3 grams of Na₂CO₃ produce how much mass of  CaCO₃?

mass of CaCO₃= 74.81 grams

74.81 grams of calcium carbonate are produced from 79.3 g of sodium carbonate.