Question

Please help asap 18 points if help and right answer please ​

Answer 1

Answer:

Lithium = 8%

Bromine = 92%

Explanation:

To calculate percent composition, you must:

- Calculate the molar mass.

- Divide the subtotal for each element's mass by the molar mass.

- Convert to a percentage

With that being said, given LiBr (Lithium Bromide), calculate the molar mass:

Lithium has an atomic weight of 7, and there is one Lithium atoms in LiBr. Bromine has an atomic weight of 80, and there is one Bromine atom in LiBr:

$1(7)\\1(80)$

Add the two products:

$80+7$

$=87$

The molar mass of LiBr is about 87 grams.

With that information, divide the subtotal of Lithium by the molar mass, and then multiply by 100 to convert to a percentage:

$\frac{7}{87}$ × $100=$

8.0459%

(Round to nearest percentage):

8%

Therefore, the percent composition of Lithium in the compound Lithium Bromide is about 8%.

Now, divide the subtotal of Bromine by the molar mass, and then multiply by 100 to convert to a percentage:

$\frac{80}{87}$ × $100=$

91.9540

(Round):

92%

Therefore, the percent composition of Bromine in the compound Lithium Bromide is about 92%.