PLEASE HELP!!!!!!!!!!!???????? I just want the answer only!
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PLEASE HELP!!!!!!!!!!!???????? I just want the answer only!

[From: ] [author: ] [Date: 12-02-21] [Hit: ]
do NOT answer my question.Which is the percent composition of bromine in the compound NaBr?A) 81.B) 79.C) 84.D) 77.......
If your username is Mrs. L, Lexi R., moouers, or Maggie, do NOT answer my question.

Which is the percent composition of bromine in the compound NaBr?

A) 81.6%
B) 79.9%
C) 84.1%
D) 77.7%

2) The name of a hydrate is calcium chloride dihydrate. What is its formula?

A) CaCl2•H4O2
B) CaCl2•2H2O
C) 2CaCl2•H2O
D) CaCl2•H2O

-
1) D
2) B

-
1(22.99gNa) + 1(79.90gBr) = 102.89gNaBr
(79.90gBr / 102.89gNaBr) x 100% = 78.0%
Depending on the periodic table you are using, this percentage may be off by a bit. I would say the answer is D.

Calcium chloride dihydrate
Ca has a charge of +2
Cl has a charge of -1
Therefore, CaCl2 would cause the charges to neutralize each other.
Dihydrate is two molecules of water, so since water is denoted H2O, you would just add a two coefficient to the front.
So the full answer would be CaCl2•2H2O (or letter B).

-
1)
D) 77.7%
bcoz molecular wt of Na is 23
molecular wt of Br is 80
and % of Br=80/103=77%

2)
B)CaCl2•2H2O
bcoz dihydrate means two water molecules
1
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