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3 years ago

Answer all the following questions by putting a circle around a letter A.B.C or D

Chemistry

1 answer:

Nataly_w [17]3 years ago

3 0

Answer:

C. 21%oxygen

Explanation:

Dry air contains 78.09% nitrogen, 20.95%oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases.

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A solution is made

Anna11 [10]

Answer:

99.3%

Explanation:

The percent by mass of the solute can be expressed as:

% mass = $\frac{MassSolute}{MassSolute+MassSolvent}$ * 100%

And for this problem:

Mass of Solute = Mass of sodium lithium chloride = 29 g

Mass of Solvent = Mass of Water

So to calculate the percent by mass first we need to calculate the mass of water, to do so we use its density (1 g/L):

202 mL is equal to (202/1000) 0.202 L.

Density water = mass water / volume

1 g/L = mass water / 0.202 L

Mass water = 0.202 g

Now we have all the data required to calculate the % mass:

% mass = $\frac{29g}{29g+0.202g}$ * 100 % = 99.3%

3 0

2 years ago

Read 2 more answers

8. Given the balanced chemical equation Br2 + 2 NaI -> 2 NaBr + I2 How many moles of sodium bromide (NaBr) could be produced

bezimeni [28]

Since we are already given the balanced equation:

$Br_{2}+2NaI$ → $NaBr+I_{2}$

We can derive the molar ratios as: 1:2:1:1

That being said, we are given 0.172 moles of bromine ( $Br_{2}$ ), so it has a ratio of 1:1 with sodium bromide ( $NaBr$ ).

So we can take from that ratio, that when 0.172 moles of bromine are used, we are, in turn, going to get 0.172 moles of sodium bromide produced.

4 0

3 years ago

A Gamma ray is a very high speed particle with no charge?

I am Lyosha [343]

Agamma ray is a very high speed particle with no charge.

3 0

2 years ago

Read 2 more answers

What is the chemical formula of the ionic compound sodium acetate?

valentina_108 [34]

Answer:

The correct answer is option A

4 0

1 year ago

Write True if the statement is correct and False if it is incorrect.

horsena [70]

T
F
F
T
F
T
T
F
T
T...............................

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3 years ago