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3 years ago

A runner competed in a 5-mile run. How many yards did she run?

Chemistry

1 answer:

vfiekz [6]3 years ago

3 0

5 miles are equivalent to 8,800 yards

so b. is the correct answer. plz like and hope it helped

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If 10.7 grams of NH4Cl is dissolved in enough water to make 800 mL of solution,what will be it's molarity

olga nikolaevna [1]

<h3><u>Answer;</u></h3>

Molarity = 0.25 M

<h3><u>Explanation;</u></h3>

Molarity is given by moles/Liter.

First we find moles:

Number of moles = Mass /molar mass

= (10.7g NH4Cl)/(53.5g/mol NH4Cl)

= 0.200 moles NH4Cl

Then we convert to liters:

= (800mL)*(1L/1000mL) = 0.800L

Therefore; molarity = 0.2moles/0.8L

= 0.25M

6 0

3 years ago

Calculate the ph of sweater which has a hydrogen ion concentration of 1 times 10 to the power of 8

telo118 [61]

Answer:

The pH of the sweater containing Hydrogen ion concentration

$[H^{+}]=1\times 10^{-8}$ is

<u></u>

Explanation:

pH = It is the negative logarithm of activity (concentration) of hydrogen ions.

pH = -log([H+])

Now, In the question the concentration of [H+] ions is :

$[H^{+}]=1\times 10^{-8}$

$pH = -log(1\times 10^{-8})$

use the relation:

$log(10^{-a})=a$

$pH= -(-8)$

pH = 8

Note : <em><u> 1 times 10 to the power of 8 must be" 1 times 10 to the power of -8"</u></em>

If the concentration is

$[H^{+}]=1\times 10^{8}$

Then pH = -8 , which is not possible . So in that case the pH calculation is by other method

5 0

3 years ago

Which of the following statements regarding spontaneous changes is false?A. Spontaneity is favored when heat is released.B. Spon

ArbitrLikvidat [17]

Answer: Option (E) is the correct answer.

Explanation:

A spontaneous reaction is defined as the process which tends to occur on its own. And, a non-spontaneous reaction is defined as a process for the completion of which we have to provide certain conditions.

For example, ice melting at $25^{o}C$ is spontaneous primarily due to the increase in molecular disorder (dispersal of matter). Also, melting of ice is taking place on its own without any external force.