Question

a mixture is known to contain mercury (ii) oxide. a 4.85 gram sample of the mixture is heated, decomposing the mercury (ii) oxide, and 2.54 L of oxygen gas are collected at 305.2 K and .967 atm. what is the percentage of mercury (ii) oxide in the mixture

Answer 1

Number of moles in mercury oxide = 0.00981 moles $O_{2}$

Number of oxide required in decomposition of mercury = 4.249 g $H_{g} O$

Percentage of mercury required = 87.6%

Evaluating the value :

First determine the number of moles of $O_{2}$ obtained using the ideal gas law.

To use the gas constant 0.0821 L-atm/mole-degree, the pressure and volume must be changed to atmospheres and liters and the temperature changed to degrees K.

To find the number of moles use

n  = $\frac{PV}{RT}$

=  735/760 x 0.254 / 0.082 x 305.15

=  0.00981 moles.$O_{2}$

The balanced equation is 2$H_{g} O$====>  2Hg  +  $O_{2}$

so a conversion factor to get grams $H_{g} O$ from moles $O_{2}$ is

  2 x 216.59 g HgO /  1 mole $O_{2}$  =  433.18.

The grams of HgO then is 433.18 x 0.00981

=  4.249 g HgO required to produce 0.00981 moles of O2 by decomposition.

The percent of HgO in the mixture is then

= 4.249 / 4.85 x 100

=  87.6%.

Mixture of mercury :

The element mercury is a pure substance. Nickel sulfate is also a pure substance but it is a compound of the elements nickel, sulfur, and oxygen.

Mercury is a compound that can be found naturally in the environment. It can be found in metal form, as mercury salts or as organic mercury compounds.

Learn more about mercury compound :

brainly.com/question/1711938

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