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3 years ago

Help! question in picture!

Chemistry

2 answers:

RUDIKE [14]3 years ago

8 0

My sister is saying it’s A, but I think it’s C. Only because I had this question in my test before.

k0ka [10]3 years ago

8 0

It’s C because I learned this last year.

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Sound waves are transverse mechanical waves. <br><br> True<br> False

allochka39001 [22]

False

Explanation:

Sound waves are longitudinal mechanical waves.

Mechanical waves are waves that requires a medium to propagate them.

A transverse wave is a wave that is propagated perpendicularly to its source.
An example is electromagnetic radiation.
A longitudinal wave is a wave that is directed parallel to their source.
Sound wave is a longitudinal wave.
It has series of rarefaction and compression along its travel path.
Rarefaction are areas of sparse particles.
Compression are areas with dense particles.

learn more:

Sound wave brainly.com/question/3619541

#learnwithBrainly

7 0

3 years ago

A method used by the U.S. Environmental Protection Agency (EPA) for determining the concentration of ozone in air is to pass the

baherus [9]

Answer: 1. $9.08\times 10^{-6}$ moles

2. 90 mg

Explanation:

$O_3(g)+2NaI(aq)+H_2O(l) \rightarrow O_2(g)+I_2(s)+2NaOH(aq)$

According to stoichiometry:

1 mole of ozone is removed by 2 moles of sodium iodide.

Thus $4.54 \times 10^{-6}$ moles of ozone is removed by = $\frac{2}{1}\times 4.54 \times 10^{-6}=9.08\times 10^{-6}$ moles of sodium iodide.

Thus $9.08\times 10^{-6}$ moles of sodium iodide are needed to remove $4.54\times 10^{-6}$ moles of $O_3$

2. $\text{Number of moles of ozone}=\frac{0.01331g}{48g/mol}=0.0003moles$

According to stoichiometry:

1 mole of ozone is removed by 2 moles of sodium iodide.

Thus 0.0003 moles of ozone is removed by = $\frac{2}{1}\times 0.0003=0.0006$ moles of sodium iodide.

Mass of sodium iodide= $moles\times {\text {molar mass}}=0.0006\times 150g/mol=0.09g=90mg$ (1g=1000mg)

Thus 90 mg of sodium iodide are needed to remove 13.31 mg of $O_3$ .

3 0

3 years ago

Methane reacts with oxygen in the following combustion reaction.

Natali5045456 [20]

The methane molecule undergoes oxidation and the carbon is oxidized to carbon dioxide and hydrogen to water.

In this reaction there is cleavage of four C-H bonds and two O=O bonds

there will be formation of two C=O bonds and four O-H bonds.

Overall due to more bond cleavage energy there will be evolution of energy. thus combustion is an exothermic reaction.

6 0

3 years ago

Read 2 more answers

What is the approximate percent by mass of potassium in KHCO3?

lozanna [386]

Answer:

The mass percent of potassium is 39%

Option C is correct

Explanation:

Step 1: Data given

Atomic mass of K = 39.10 g/mol

Atomic mass of H = 1.01 g/mol

Atomic mass of C = 12.01 g/mol

Atomic mass of O = 16.0 g/mol

Step 2: Calculate molar mass of KHCO3

Molar mass KHCO3 = 39.10 + 12.01 + 1.01 + 3*16.0

Molar mass KHCO3 = 100.12 g/mol

Step 3: Calculate mass percent of potassium (K)

%K = (atomic mass of K / molar mass of KHCO3) * 100%

%K = (39.10 / 100.12) * 100%

%K = 39.05 %

The mass percent of potassium is 39%

Option C is correct

8 0

3 years ago

What is the number of moles in 432g Ba(NO3)2

777dan777 [17]

First there is a need to calculate the molar mass of Ba(NO₃)₂:

137.3 + 2 (14.0) + 6 (16) = 261.3 grams/mole

The molar mass, denoted by M in chemistry refers to a physical characteristic illustrated as the mass of a given component divided by the amount of the component. The molar masses are always denoted in grams/mole.

After finding the molar mass, the number of moles can be identified as:

432 grams / 261.3 g/mol = 1.65 moles of Ba(NO₃)₂.

3 0

3 years ago