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TiliK225 [7]
3 years ago
10

Hello, I would really appreciate it if you guys can answer the question below, it is for marks and I do not know the answer for

this one so please help I only have 19 min left.

Chemistry
1 answer:
Taya2010 [7]3 years ago
3 0

Answer:

Two human needs are food and water. We need food to survive so we dont starve to death. And water is most important because without water after around five days, you die. Heat technology could be fire. We use fire to distill salt water. Distilling salt water boils the bacteria and so it would be safe to drink. We also use fire to cook the food we have gotten or hunted so we dont get infected with deadly bacteria and viruses.

Explanation:

Hope this helps. Have a nice day!

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Measuring the surface of an oil painting and finding its dimensions 12 to be  12 inches
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The following is an example of what type of chemical reaction?
Svetlanka [38]
This is a D. combustion reaction

That is because you add O2 which is necessary for a combustion, while the results are CO2 and water. What you are missing is a ---> after the 2O2 (g)
4 0
3 years ago
A rigid tank that contains 2 kg of N2 at 25°C and 550 kPa is connected to another rigid tank that contains 4 kg of O2 at 25°C an
koban [17]

Answer:

The volume in the first tank = 0.32 m^{3}

The volume in the second tank = 2.066 m^{3}

The  final pressure of the mixture = 203.64 K pa

Explanation:

<u>First Tank </u>

Mass = 2 kg

Pressure = 550 k pa

Temperature = 25 °c = 298 K

Gas constant for nitrogen = 0.297 \frac{KJ}{Kg K}

From the ideal gas equation

P V = m R T

550 × V = 2 × 0.297 × 298

V = 0.32 m^{3}

This is the volume in the first tank.

<u>Second tank</u>

Mass =  4 kg

Pressure = 150 K pa

Temperature = 25 °c = 298 K

Gas constant for oxygen = 0.26  \frac{KJ}{Kg K}

From the ideal gas equation

P V = m R T

150 × V = 4 × 0.26 × 298

V = 2.066 m^{3}

This is the volume in the second tank.

This is the iso thermal mixing. i.e.

P_{3} V_{3}  = P_{1} V_{1} + P_{2} V_{2} ----- (1)

V_{3}  = V_{1}  + V_{2}

V_{3}  = 0.32 + 2.066

V_{3}  = 2.386 \ m^{3}

Put this value in equation (1)

P_{3} × 2.386 =  550 × 0.32 + 150 × 2.066

P_{3} = 203.64 K pa

Therefore the  final pressure of the mixture = 203.64 K pa

3 0
3 years ago
The standard enthalpy of formation of Ca2+ (g) (∆H = 1934 kJ/mol)
Alex73 [517]

Answer:

see explanation

Explanation:

The process of ionization to produce cations is endothermic. For formation of Ca⁺² two ionization steps need be illustrated as follows...

1st ionization step: Ca° + 590Kj => Ca⁺ + e⁻

2nd ionization step: Ca⁺ + 1151Kj => Ca⁺² + e⁻

__________________________________-

Net Ionization Rxn: Ca° + 1741Kj => Ca⁺² + 2e⁻

6 0
3 years ago
I need help fast...........
guapka [62]

Answer:

I think its might be 1 because the ionic numbers for CA is +2 and for P its +3

8 0
2 years ago
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