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3 years ago

WORTH 20 POINTS HELP PLEASE

Chemistry

1 answer:

Damm [24]3 years ago

5 0

Answer:

The answers to your questions are below

Explanation:

Physical change is when matter changes its form but is still the same substance.

Chemical change is when matter changes its composition.

iron and oxygen from rust It's a chemical change because iron and oxygen form a new compound different from the reactants.

iron is denser brightly when ignited . This is a chemical property because iron reacts with oxygen.

oil and water do not mix it's a physical change, oil and water are in touch but they do not react.

mercury melts at -39°C it's a physical property because mercury changes from solid to liquid but it still is mercury.

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On which body in the Solar system would some life forms from Earth be most likely to survive?

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Answer: I would think Europa.

Explanation:

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3 years ago

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boyakko [2]

Answer: The answer to the first one is the second option and the answer for the second one is the first option.

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2 years ago

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A gaseous mixture of O2 and N2 contains 37.8% nitrogen by mass. What is the partial pressure of oxygen in the mixture if the tot

kondor19780726 [428]

Answer: The partial pressure of oxygen in the mixture if the total pressure is 525 mmHg is 310 mm Hg

Explanation:

mass of nitrogen = 37.8 g

mass of oxygen = (100-37.8) g = 62.2 g

Using the equation given by Raoult's law, we get:

$p_A=\chi_A\times P_T$

$p_{O_2}$ = partial pressure of $O_2$ = ?

$\chi_{O_2} = mole fraction of O_2=\frac{\text{Moles of }O_2}{\text{Total moles}}$

$P_{T}$ = total pressure of mixture = 525 mmHg

${\text{Moles of }O_2}=\frac{\text {Given mass}}{\text {Molar mass}}=\frac{62.2g}{32g/mol}=1.94moles$

${\text{Moles of }N_2}=\frac{\text {Given mass}}{\text {Molar mass}}=\frac{37.8g}{28g/mol}=1.35moles$

Total moles = 1.94 + 1.35 = 3.29 moles

$\chi_{O_2}=\frac{1.94}{3.29}=0.59$

$p_{O_2}=\chi_{O_2}\times P_T=0.59\times 525=310mmHg$

Thus the partial pressure of oxygen in the mixture if the total pressure is 525 mmHg is 310 mm Hg

7 0

3 years ago

10. Make your own unique problem for your classmates to solve for the

babymother [125]

Answer:

Explanation:

<u>Problem</u>:

In a gender based experiment, the blood pressure of different ages of men is been checked and recorded to determine if there is any correlation. What will be the independent, dependent and controlled variables?

<u>Answer</u>:

A controlled variable is the variable that is left constant throughout the course of an experiment. The controlled variable here is the gender.

A dependent variable is the variable that is been determined or measured during the course of an experiment. The dependent variable here is the blood pressure.

An independent variable is the variable that is intentionally or decidedly altered during the course of an experiment. The independent variable here is the age.

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3 years ago

Products of MnO + CL2

Alenkinab [10]

If the equation is complete the products would be manganese chloride and oxygen gas would be given off.

MnCl2 + O2

3 0

3 years ago