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3 years ago

14. A researcher Is curious to find out what effect classical music has on people's level of relaxation

Chemistry

1 answer:

Dima020 [189]3 years ago

3 0

Answer:

It should be "B"

Explanation:

:) :) :) :) :) :)

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Hey I'm a newbie any help please with this

solniwko [45]

6 A
7 A
8 B
9 B
10 A
11 C

4 0

3 years ago

A gas used to extinguish fires is composed of 75 % CO2 and 25 % N2. It is stored in a 5 m3 tank at 300 kPa and 25 °C. What is th

tatyana61 [14]

Answer : The partial pressure of the $CO_2$ in the tank in psia is, 32.6 psia.

Explanation :

As we are given 75 % $CO_2$ and 25 % $N_2$ in terms of volume.

First we have to calculate the moles of $CO_2$ and $N_2$ .

$\text{Moles of }CO_2=\frac{\text{Volume of }CO_2}{\text{Volume at STP}}=\frac{75}{22.4}=3.35mole$

$\text{Moles of }N_2=\frac{\text{Volume of }N_2}{\text{Volume at STP}}=\frac{25}{22.4}=1.12mole$

Now we have to calculate the mole fraction of $CO_2$ .

$\text{Mole fraction of }CO_2=\frac{\text{Moles of }CO_2}{\text{Moles of }CO_2+\text{Moles of }N_2}$

$\text{Mole fraction of }CO_2=\frac{3.35}{3.35+1.12}=0.75$

Now we have to calculate the partial pressure of the $CO_2$ gas.

$\text{Partial pressure of }CO_2=\text{Mole fraction of }CO_2\times \text{Total pressure of gas}$

$\text{Partial pressure of }CO_2=0.75mole\times 300Kpa=225Kpa=225Kpa\times \frac{0.145\text{ psia}}{1Kpa}=32.625\text{ psia}$

conversion used : (1 Kpa = 0.145 psia)

Therefore, the partial pressure of the $CO_2$ in the tank in psia is, 32.6 psia.

3 0

3 years ago

According to Newton's third law of motion, for every action force, there is

Nonamiya [84]

Answer:

A. an equal and opposite reaction force

Explanation:

This means that there is a natural reaction of force

7 0

3 years ago

Is heating an aluminum pan a chemical or physical reaction

Sedbober [7]

Answer: chemical

Explanation: whenever heat is applied, it indicates a chemical change

4 0

3 years ago

The main factor that influences the direction of any periodic trend across a period is ______.

aalyn [17]

Answer:

The correct option is B

Explanation:

The number of valence electron(s) increases across the period and thus influences the direction of periodic trend of electronegativity, electron affinity and ionization energy across the period. Thus, making option B the answer.

It should be noted that option A is wrong because elements in the same period generally have the same number of electron shells and thus the distance of this shells from the nucleus remains the same throughout the same period and thus option C is also wrong. Option D is wrong because the periodic trends have to do with chemical reactions which actually involves electrons and not protons.

3 0

3 years ago