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4 years ago

Can someone help.? thanks :)

Chemistry

1 answer:

laila [671]4 years ago

4 0

Answer:

1. Equation: 2x + 3 = 9x - 11

2. Each row has 2 chairs

Explanation:

The variable x represents the number of chairs in each row.

1. She can form 2 rows of a given length with 3 chairs left over.

Thus, she has:

number of rows number of chairs in chairs number of chairs

each row left over she has

2 x 3 2x + 3

2. She can form 9 rows of the same length if she gets 11 more chairs.

That means that she is short in 11 chairs to have 9x chairs, or that she has 11 less chairs than 9x chairs. Then she has:

9x - 11

3. Equation:

Then, number of chairs she has is 2x + 3 and, also, 9x - 11, which allows to set the equation:

2x + 3 = 9x -11

4. Solve the equation:

9x - 2x = 3 + 11

7x = 14

x = 2

Therefore, each row has 2 chairs, and she has 2x + 3 = 4 + 3 = 7 chairs.

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Answer:

Option D. KBr < KCl < NaCl

Explanation:

We'll begin by calculating the number of mole of each sample.

This can be obtained as follow:

For NaCl:

Mass = 1 g

Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol

Mole of NaCl =?

Mole = mass /Molar mass

Mole of NaCl = 1/58.5

Mole of NaCl = 0.0171 mole

For Kbr:

Mass = 1 g

Molar mass of KBr = 39 + 80 = 119 g/mol

Mole of KBr =?

Mole = mass /Molar mass

Mole of KBr = 1/119

Mole of KBr = 0.0084 mole

For KCl:

Mass = 1 g

Molar mass of KCl = 39 + 35.5 = 74.5 g/mol

Mole of KCl =?

Mole = mass /Molar mass

Mole of KCl = 1/74.5

Mole of KCl = 0.0134 mole

Summary

Sample >>>>>>>> Number of mole

NaCl >>>>>>>>>> 0.0171

KBr >>>>>>>>>>> 0.0084

KCl >>>>>>>>>>> 0.0134

Arranging the number of mole of the sampl in increasing order, we have:

KBr < KCl < NaCl

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Can someone help.? thanks :)​

Can someone help.? thanks :)