How many grams of zinc would you start with if you wanted to prepare 5.55 L of H2 at 288 mm Hg and 29.5 ∘C?

5.56g

Explanation:

Given parameters:

Volume of H₂  = 5.55L

Pressure of H₂  = 288mmHg

Temperature of H₂  = 29.5°C

Unknown:

Mass of zinc = ?

Solution:

To start with, let us write the reaction equation of this simple displacement reaction:

        Zn +  2HCl   →  ZnCl₂   +   H₂

Now we have to work from the known or given compound to the unknown.

The known here is the hydrogen gas produced. From the parameters given, let us solve for the number of moles using the ideal gas law;

              PV  = nRT

          take the given species to appropriate units;

                   288mmHg  to atm gives;

                 760mmHg gives 1atm

                 288mmHg will give     = 0.38atm

      take the temperature to k;

           29.5°C ;     29.5 + 273  = 302.5K

From the ideal gas equation:

 P is the pressure

 V is the volume

 n is the number of moles

 R is the gas constant

 T is the temperature

Input the parameters and solve for n;

               0.38 x 5.55  = n x 0.082 x 302.5

                         n  = 0.085moles

From the balanced reaction equation;

              1 mole of H₂ is produced from 1 mole of Zn

             0.085moles of H₂ will be produced from 0.085 moles of Zn

Mass of Zn  = number of moles of Zn x molar mass of Zn

                        = 0.085 x 65.4

                         = 5.56g

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.

the answer is definitely c.