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2 years ago

I know that one of them is multiple choice but i’m not sure which one it is.

Chemistry

1 answer:

Evgen [1.6K]2 years ago

5 0

Explanation:

1. neutrons

2. protons

3. protons and neutrons

4. neutrons

5. electrons

I'm not sure with 1 and 4, sorry :<

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A mixture of gases with a pressure of 800.0 mm hg contains 60% nitrogen and 40% oxygen by volume. what is the partial pressure o

klasskru [66]

Hello!

We have the following statement data:

Data:
$P_{Total} = 800 mmHg$
$P\% N_{2} = 60\%$
$P\% O_{2} = 40\%$
$P_{partial} = ? (mmHg)$

As the percentage is the mole fraction multiplied by 100:

 $P = X_{ O_{2} }*100$

The mole fraction will be the percentage divided by 100, thus:
What is the partial pressure of oxygen in this mixture?

$X_{ O_{2} } = \frac{P}{100}$
$X_{ O_{2}} = \frac{40}{100}$
$\boxed{X_{ O_{2}} = 0.4}$

To calculate the partial pressure of the oxygen gas, it is enough to use the formula that involves the pressures (total and partial) and the fraction in quantity of matter:

In relation to $O_{2}$ :

$\frac{P O_{2} }{P_{total}} = X_O_{2}$
$\frac{P O_{2} }{800} = 0.4$
$P_O_{2} = 0.4*800$
$\boxed{\boxed{P_O_{2} = 320\:mmHg}}\end{array}}\qquad\quad\checkmark$

Answer:
b. 320.0 mm hg

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3 years ago

Emma strikes a match and sets some logs on fire. As the fire burns, which two forms of energy are released?

Ivanshal [37]

Answer:

Explanation:

There are changes in the chemical composition of the word.

There's light energy given off.

There's heat energy given up.

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2 years ago

An aqueous solution of potassium sulfate (K2SO4) has a freezing point of -2.24

iragen [17]

An aqueous solution of potassium sulfate exhibits colligative properties. Colligative properties are properties that depends on the concentration of a substance in a solution. These properties are freezing point depression, vapor pressure lowering, osmotic pressure and boiling point elevation. For this problem we use the concept of freezing point depression since we are given the freezing point of the solution. Freezing point depression is as:

ΔT = -k(f) x m x i
-2.24 - 0 = -1.86 x m x 3
m = 0.4014

Thus, the molality of the solution is 0.4014.

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3 years ago

A group of students is investigating how the addition of salt impacts the floatation of an egg in water. Four identical cups wer

soldier1979 [14.2K]

Answer: The correct answer is Option 1.

Explanation:

Control group is the group used in the experiment by the researchers in which no change in the variable is done. It is then set as a benchmark for the groups which are being tested.

We are given 4 groups which are being experimented for the flotation of an egg in water. As in Cup 1, there is no addition of salt and hence there is no change in the variables. So, this is set as a benchmark fro the cups which are further used in the experiment conducted.

Hence, the correct answer is Option 1.

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3 years ago

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Genrish500 [490]

Anti-acids because they contain Alkaline ion that chemically neutralizes stomach acid

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2 years ago