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4) A sample of sodium bromide, NaBr, has a mass percentage of sodium of 22.34%.

a) If the sample of sodium bromide were contaminated with sodium chloride, NaCl, would the mass percentage of Na in the sample be higher or lower than the pure sample? Justify your claim.

b) If the sample of sodium bromide were contaminated with sodium iodide, NaI, would the mass percentage of Na in the sample be higher or lower than the pure sample? Justify your claim

Respuesta :

pokhrelarahanta5

Explanation:

The trick here is to realize the every sample of sodium bromide, regardless of its mass, will contain

22.34

%

sodium by mass.

This is true because sodium and bromide always combine in definite proportions, i.e. stable ratios by mass, to form sodium bromide.

Now, a

22.34

%

percent concentration by mass means that every

100 g

of sodium bromide will contain

22.34 g

of sodium and

100 g

−

22.34 g

=

77.66 g Br

Therefore, you can say that the mass ratio that exists between sodium and bromine in any sample of sodium bromide will be

22.34 g Na

77.66 g Br

=

22.34

77.66

You can thus use this definite proportion to say that a

5.69 g

sample of sodium bromide will contain

5.69

g NaBr

⋅

22.34 g Na

100

g NaBr

=

1.271 g Na

=

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

∣

∣

a

a

1.27 g Na

a

a

∣

∣

−−−−−−−−−−−−−

The answer is rounded to three sig figs.

You can use the known definite proportion to find the mass of bromide present in the sample

1.271

g NaBr

⋅

77.66 g Br

22.34

g NaBr

=

4.42 g Br

This checks out because

mass of NaBr sample



5.69 g

−

mass of Na



1.27 g

=

mass of Br



4.42 g

batolisis

The answers to your questions are ;

a) The mass percentage of Na in the sample will be higher in the sample

b) The mass percentage of Na in the sample will be be lower in the sample

Given that:

Mass percentage of sodium contained in sodium Bromide = 22.34%

a) Determine if the mass percentage of Na will be higher or lower when sodium Bromide is contaminated with sodium chloride  

mass percentage of Na in sodium bromide

= ( mass of Na / mass of NaBr )*100

The mass of sodium in NaBr and NaCl is the same while the mass of Br is not same ( greater than ) as the mass of Cl.  hence when NaBr is contaminated with NaCl the total mass of  in percentage NaBr will decrease. and This decrease in mass of NaBr will lead to a decrease/lower mass percentage of Na in the sample

b) When NaBr is contaminated with NaI

The mass of Na is the same in NaBr and NaI while the mass of I is not the same ( greater than ) as the mass of Br, therefore the total mass will increase and the increase in the Total mass in percentage will lead to an increase/higher value of Na in the given sample.

hence the mass percentage of Na will decrease when NaBr is contaminated with NaCl while the mass percentage of Na will increase when NaBr is contaminated with NaI

Learn more : https://brainly.com/question/3244231

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