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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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Plant Cell
musickatia [10]

Answer:

it's the chloroplast but I'm not sure which on is it it might be the F.

6 0
3 years ago
A sample of gas occupies a volume of 61.5 mL . As it expands, it does 130.1 J of work on its surroundings at a constant pressure
Lesechka [4]

Answer:

the final volume of the gas is V_2 = 1311.5 mL

Explanation:

Given that:

a sample gas has an initial volume of 61.5 mL

The workdone = 130.1 J

Pressure = 783 torr

The objective is to determine the final volume of the gas.

Since the process does 130.1 J of work on its surroundings at a constant pressure of 783 Torr. Then, the pressure is external.

Converting the external pressure to atm ; we have

External Pressure P_{ext}:

P_{ext} = 783 \ torr \times \dfrac{1 \ atm}{760 \ torr}

P_{ext} = 1.03 \ atm

The workdone W = P_{ext}V

The change in volume ΔV= \dfrac{W}{P_{ext}}

ΔV = \dfrac{130.1 \ J  \times \dfrac{1 \ L  \ atm}{ 101.325 \ J}  }{1.03 \ atm }

ΔV = \dfrac{1.28398717 }{1.03  }

ΔV = 1.25 L

ΔV = 1250 mL

Recall that the initial  volume = 61.5 mL

The change in volume V is \Delta V = V_2 -V_1

-  V_2= -  \Delta V  -V_1

multiply through by (-), we have:

V_2=   \Delta V+V_1

V_2 =  1250 mL + 61.5 mL

V_2 = 1311.5 mL

∴ the final volume of the gas is V_2 = 1311.5 mL

5 0
3 years ago
Which of these is the best evidence that a chemical reactions occurs when coal burns?
laila [671]

Answer:

It’s b even check quizzes

Explanation:

3 0
3 years ago
Read 2 more answers
What is the molarity to the nearest hundredth of a solution made by dissolving 1.71 moles of NaOH in enough water to produce an
Natali [406]

Answer:

Explanation:

50 is the volume

5 0
2 years ago
Read 2 more answers
A 1.85 kg textbook is sitting on a bookshelf 2.23 m above the floor. How much potential energy does it have?
neonofarm [45]

Answer:

\boxed {\boxed {\sf 40.4299 \ Joules}}

Explanation:

Potential energy is energy due to position. It is the product of mass, height, and acceleration due to gravity.

PE= m \times g \times h

The mass of the textbook is 1.85 kilograms. Assuming this is on Earth, the acceleration due to gravity is 9.8 meters per square second. The height is 2.23 meters.

  • m= 1.85 kg
  • g= 9.8 m/s²
  • h= 2.23 m

Substitute the values into the formula.

PE = 1.85 \ kg \times 9.8 \ m/s^2 \times 2.23 \ m

Multiply the first 2 numbers together.

PE=18.13 \ kg*m/s^2 *2.23 \ m

Multiply again.

PE= 40.4299 \ kg*m^2/s^2

  • 1 kilogram square meter per square second (1 kg*m²/s²) is equal to 1 Joules (J)
  • Our answer of 40.4299 kg*m²/s² is equal to 40.4299 J

PE= 40.4299 \ J

The textbook has <u>40.4299 Joules of potential energy.</u>

7 0
3 years ago
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