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2 years ago

Abbey always gets zits on her chin and she can't figure out

1 answer:

6 0

Experiment has to do with the examination of the relationship between the dependent variable and the independent variable.

<h3>What is an experiment?</h3>

The term experiment has to do with the examination of the relationship between the dependent variable and the independent variable. In this case, the independent variable is the variable that we can manipulate while the dependent variable the one that changes when we manipulate the independent variable.

Let us now identify the variables in the experiment;

independent variable; the type of product used

constant variable; length of time that the product is used

Hypothesis; The Zits could be cleared from her face by a skin care product

The control group is the washing with water

The experimental group is the washing with a product

The constant is the face on which the product s used.

Learn more about experiment;brainly.com/question/11256472

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Missing parts;

Abbey always gets zits on her chin and she can’t figure out the best method to get rid of them. She decides to test several products to see which clears her face up fastest: washing with soap and water, washing with an acne face wash from the pharmacy, and washing her face with organic oils. For one week she just washes her face with water. The next week she washes every day with soap and water. The following week she uses the acne wash, and the last week she uses the organic oils. Each week she records the number of zits she has on her chin at the end of the day. What is the independent variable? What is the constant variable? What is the hypothesis? What is the control group? What is the experimental group? What is the constant?

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Answer:

3.38%

Explanation:

Given that;

the mass of the whole milk sample = 100 g

volume of HCl = 100 mL = 0.1 L

molarity of HCl = 0.5 M

volume of NaOH = 34.50 mL = 0.0345 L

molarity of NaOH = 0.3512 M

Since we knew the molarity and volume of both HCl and NaOH; we can calculate their corresponding number of moles present.

So, number of moles of HCl = molarity of HCl × volume of HCl

number of moles of HCl = 0.5 M × 0.100 mL

= 0.05 mole

number of moles of NaOH = Molarity of NaOH × Volume of NaOH

number of moles of NaOH = 0.3512 M × 0.0345 L

= 0.012 mole

From the question, we can deduce that the number of HCl that is consumed by NH₃ is equal to the number of moles of HCl that is consumed by NaOH.

SO, number of moles of HCl consumed by NH₃ = Total moles of HCl - moles of HCl consumed by NaOH

= 0.05 mole - 0.012 mole

= 0.038 mole

However, to determine the mole of NH₃ present , we have:

number of moles of NH₃ present = number of moles of HCl consumed by NH₃ = 0.038

∴ the mass of Nitrogen with the molecular weight (14.0 g/mol) = 0.038 moles × 14.0 g/mol

= 0.530 g

Now, the percentage of Nitrogen can be calculated as;

$percentage of nitrogen =\frac{mass of nitrogen}{mass of the whole milk sample} *100$

$percentage of nitrogen =\frac{0.530g}{100g} *100$

$percentage of nitrogen =0.530%$ %

the percentage of protein in the sample = CP × %age of N

where CP is given as 6.38

∴ the percentage of protein in the sample = 6.38 × 0.530%

the percentage of protein in the sample = 3.3814%

the percentage of protein in the sample = 3.38%

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every action of has an opposite and equal reaction so we know that the rifle moved back toward her shoulder because the bullet that was fired out of gun was moving at a very high speed.

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Investigate why some element’s symbols derived from their old names.

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Answer:

you know just in order to bring that nostalgia into chemists minds

Explanation:

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3 years ago

True or false: If you rub things together, electrons can move from one atom to another?

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Answer:

true

Explanation:

there is a transfer of electrons from one material to the other material. This causes one object to become positively charged (the electron loser) and the other object to become negatively charged (the electron gainer).

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A chemist wants to extract copper metal from copper chloride solution. The chemist places 0.50 grams of aluminum foil in a solut

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Answer:

Approximately 0.36 grams, because copper (II) chloride acts as a limiting reactant.

Explanation:

It is a stichiometry problem.

We should write the balance equation of the mentioned chemical reaction:

2Al + 3CuCl₂ → 3Cu + 2AlCl₃.

It is clear that 2.0 moles of Al foil reacts with 3.0 moles of CuCl₂ to produce 3.0 moles of Cu metal and 2.0 moles of AlCl₃.

Also, we need to calculate the number of moles of the reported masses of Al foil (0.50 g) and CuCl₂ (0.75 g) using the relation:

n = mass / molar mass

The no. of moles of Al foil = mass / atomic mass = (0.50 g) / (26.98 g/mol) = 0.0185 mol.

The no. of moles of CuCl₂ = mass / molar mass = (0.75 g) / (134.45 g/mol) = 5.578 x 10⁻³ mol.

From the stichiometry Al foil reacts with CuCl₂ with a ratio of 2:3.

∴ 3.85 x 10⁻³ mol of Al foil reacts completely with 5.578 x 10⁻³ mol of CuCl₂ with (2:3) ratio and CuCl₂ is the limiting reactant while Al foil is in excess.

From the stichiometry 3.0 moles of CuCl₂ will produce the same no. of moles of copper metal (3.0 moles).
So, this reaction will produce 5.578 x 10⁻³ mol of copper metal.
Finally, we can calculate the mass of copper produced using:

mass of Cu = no. of moles x Atomic mass of Cu = (5.578 x 10⁻³ mol)(63.546 g/mol) = 0.354459 g ≅ 0.36 g.

So, the answer is:

Approximately 0.36 grams, because copper (II) chloride acts as a limiting reactant.

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4 years ago