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3 years ago

Can someone please help me

Chemistry

1 answer:

AlekseyPX3 years ago

5 0

Answer:

Physical changes are when the object can be returned back into their original form. Chemical changes are when the object gets changed and can't get reversed.

Explanation:

1-physical

2-physical

3-physical

4-chemical

5-chemical

6-chemical

7-physical

8-chemical

9-chemical

10-chemical

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2. The Food and Drug Administration (FDA) mandates that all vinegar sold in the United States must have a minimum concentration

Scilla [17]

Answer:

The minimum molarity of acetic acid in vinegar according to given standards is 0.6660 mol/L.

Explanation:

4% acetic acid by mass means that 4 gram of acetic acid in 100 g solution.

Given that density of the vinegar is same is that of water = 1 g/mL

Mass of the vinegar solution = 100 g

Volume of the vinegar solution = V

$Density=\frac{Mass}{Volume}$

$1 g/mL=\frac{100 g}{V}$

V = 100 mL = 0.1 L

Moles of acetic acid = $\frac{4 g}{60.052 g/mol}=0.0666 mol$

$Molarity=\frac{\text{Moles of solute}}{\text{Volume of solution(L)}}$

$M=\frac{0.0666 mol}{0.1 L}=0.6660 mol/L$

The minimum molarity of acetic acid in vinegar according to given standards is 0.6660 mol/L.

4 0

4 years ago

Explain the neutralization of vitamin c with sodium hydrogen carbonate?

mars1129 [50]

Scientists have known the consequences of mixing sodium bicarbonate and vitamin C ever since 1936, when a study on the subject was published in the "Journal of Nutrition." The authors of this study measured the amount of vitamin C recovered from the urine of people who drank a fixed amount of orange juice. The authors determined that the amount of vitamin C excreted was decreased by administration of sodium bicarbonate. Followup studies in the 1940s showed that this effect was due to the neutralization of the vitamin C by the sodium bicarbonate.

3 0

3 years ago

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Which of the following properties of an unknown substance would allow it to be classified as a mixture? The unknown substance

Nadya [2.5K]

Answer:

D. has different properties when sampled in different areas.

Explanation:

The general property of a mixture says that each substance or component in a mixture has its individual or different property which can be separated on the basis of different methods.

Such as a mixture of oil and water is a heterogeneous mixture and have different properties or different densities, which helps them to be sampled in different areas.

Hence, the correct answer is "D".

6 0

3 years ago

Two solutions are combined in a beaker. One solution contains 500.0 g of potassium phosphate and the other contains 500.0 g of c

Anna [14]

The question is incomplete. The complete question is

Two solutions are combined in a beaker. One solution contains 500.0 g of potassium phosphate and the other contains 500.0 g of calcium nitrate. A double displacement reaction occurs. What mass of each of the following substances is present when the reaction stops. A) potassium phosphate remaining B) calcium nitrate g remaining C) calcium phosphate formed D) potassium nitrate g formed

Answer:

a)84.91g

b)8.20g

c)316.4g

d)616.73g

Explanation:

The equation of the reaction:

2K3PO4(aq) + 3Ca(NO3)2 (aq)-------> 6KNO3(aq) + Ca3(PO4)2(s)

Molar mass of potassium phosphate= 212.27 g/mol

Amount of potassium phosphate= 500/212.27= 2.4 moles

Molar mass of calcium nitrate= 164.088 g/mol

Amount of calcium nitrate= 500/164.088=3.05moles

a) amount of potassium phosphate reacted according to reaction equation= 2 moles

Amount of potassium phosphate remaining= 2.4-2=0.4 moles

Mass of potassium phosphate remaining= 0.4×212.27=84.91g

b) Amount of calcium nitrate reacted according to reaction equation=3

Amount of calcium nitrate remaining=3.05-3= 0.05

Mass of calcium nitrate remaining= 0.05×164.088= 8.20g

c) since calcium nitrate is the limiting reactant, we use to estimate the mass of products formed.

From the reaction equation,

3 moles of calcium nitrate yields 1 mole of calcium phosphate

3.05 moles of calcium nitrate yields 3.05/3 = 1.02 moles of calcium phosphate

Molar Mass of calcium phosphate= 310.18 g/mol

Mass of calcium phosphate produced= 1.02×310.18= 316.4g

3 moles of calcium nitrate yields 6 moles of potassium nitrate

3.05 moles of calcium nitrate yields 3.05×6/3= 6.1 moles of potassium nitrate

Molar mass of potassium nitrate = 101.1032 g/mol

Mass of potassium nitrate formed= 6.1× 101.1032= 616.73g

6 0

4 years ago

The mixture which contains elements only is (a) air (b) brass (c) mineral water (d) seawater

Sholpan [36]

Answer:

So yes! A mixture can contain just elements if those elements are not chemically reactive to one another. Air is a great example of an elemental mixture as it contains nitrogen, oxygen, and argon (along with some other compounds).

Explanation:

hope this helps you :)

4 0

3 years ago

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