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3 years ago

Question 2

Chemistry

1 answer:

andrezito [222]3 years ago

3 0

Answer:

A. Peroxide breaking down into water and oxygen

Explanation:

Generally when it comes to changes, there are physical and chemical changes. In physical changes, there are no new substances been formed, however in chemical change new substances are formed.

A. Peroxide breaking down into water and oxygen

This is a chemical change.

B . Bubbles forming when a pot of water is heated

This is a physical change

C. A pair of jeans soaked in water drying after hanging outside

This is a physical change

D . A block of ice decreasing in size due to a change in temperature

This is a physical change.

Only option A is different from the rest,hence this is the answer.

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iVinArrow [24]

The answer of what i got was b

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4 years ago

At a pressure of 9.25×10−14 atm and an ordinary temperature of 300.0 K , how many molecules are present in a volume of 1.10 cm3

statuscvo [17]

Answer:

2.49 × 10⁶ molecules

Explanation:

Given data

Pressure (P): 9.25 × 10⁻¹⁴ atm

Temperature (T): 300.0 K

Volume (V): $1.10cm^{3} .\frac{1mL}{1cm^{3}} .\frac{1L}{1000mL} =1.10\times 10^{-3} L$

We can calculate the moles of gas using the ideal gas equation.

P × V = n × R × T

n = P × V / R × T

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n = 4.13 × 10⁻¹⁸ mol

1 mole contains 6.02 × 10²³ molecules (Avogadro's number). The number of molecules in 4.13 × 10⁻¹⁸ moles is:

4.13 × 10⁻¹⁸ mol × (6.02 × 10²³ molecule/1 mol) = 2.49 × 10⁶ molecule

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3 years ago

A scuba diver is using scuba gear to breathe under water. The pressure on her lungs is 2.5 atm and her lung volume is 4.4 L. Wha

nikdorinn [45]

Answer:

Explanation:

The volume can be used by using the formula for Boyle's law which is

$P_1V_1 = P_2V_2 \\$

where

P1 is the initial pressure

P2 is the final pressure

V1 is the initial volume

V2 is the final volume

Since we're finding the final volume

$V_2 = \frac{P_1V_1}{P_2} \\$

We have

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We have the final answer as

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inna [77]

Answer:

Explanation:

The specific heat capacity=quantity of heat in joule/mass×change in temperature

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which is 20

therefore

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