How many grams of ZnCl2 will be produced from 26.0g of Zn and 42.0g of HCl. Round to three significant figures

The mass of zinc chloride produced in the reaction is 54.1 grams

Explanation:

To calculate the number of moles, we use the equation:

    .....(1)

Given mass of zinc = 26 g

Molar mass of zinc = 65.4 g/mol

Putting values in equation 1, we get:

Given mass of HCl = 42 g

Molar mass of HCl = 36.5 g/mol

Putting values in equation 1, we get:

The chemical equation for the reaction of zinc and HCl follows:

By Stoichiometry of the reaction:

1 mole of zinc reacts with 2 moles of HCl

So, 0.397 moles of zinc will react with = of HCl

As, given amount of HCl is more than the required amount. So, it is considered as an excess reagent.

Thus, zinc metal is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

1 mole of zinc produces 1 mole of zinc chloride

So, 0.397 moles of zinc will produce = of zinc chloride

Now, calculating the mass of zinc chloride from equation 1, we get:

Molar mass of zinc chloride = 136.3 g/mol

Moles of zinc chloride = 0.397 moles

Putting values in equation 1, we get:

Hence, the mass of zinc chloride produced in the reaction is 54.1 grams

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.