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2 years ago

The answer to the problem: 3.542 - 2.1 = _____, written to the correct number of significant digits is:

Chemistry

2 answers:

VMariaS [17]2 years ago

7 0

1.442 or 1.4

Round it to the nearest number

7nadin3 [17]2 years ago

7 0

Answer:

1.442

Explanation:

3.542-2.1

=1.442

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Which statement describes the masses of the particles that make up an atom?

Novay_Z [31]

The mass of the atom is equal to the sum of the number of protons and the number of neutrons. In a neutral atom, the number of protons is equal to the number of electrons. The atomic number meanwhile of an atom is equal to the number of protons of the atom.

6 0

2 years ago

How does the vegetation surface type affect the amount of runoff

maxonik [38]

Answer:

The type of vegetation a surface does affect the water coming from above to sink in or runoff. 

Explanation:

This is how the vegetation affects the runoff:-

The leaves and stems present in the vegetation do not let the water fall directly on the soil and makes the process rather slow which makes the water to get to the ground slowly and sink in properly inside the soil rather than running off.

If the vegetation present is dense with there was being hairy then also the water would not run out and will get absorbed by the roots letting the soil intact

5 0

2 years ago

How many moles of methanol must be added to 4.50 kg of water to lower its freezing point to -11.0 ∘c? for each mole of solute, t

DochEvi [55]

Given:

Mass of solvent water = 4.50 kg

Freezing point of the solution = -11 C

Freezing point depression constant = 1.86 C/m

To determine:

Moles of methanol to be added

Explanation:

The freezing point depression ΔTf is related to the molality m through the constant kf, as follows:

ΔTf = kf*m

where ΔTf = Freezing point of pure solvent (water) - Freezing pt of solution

ΔTf = 0 C - (-11.0 C) = 11.0 C

m = molality = moles of methanol/kg of water = moles of methanol/4.50 kg

11.0 = 1.86 * moles of methanol/4.50

moles of methanol = 26.613 moles

Ans: Thus around 26.6 moles of methanol should be added to 4.50 kg of water.

3 0

3 years ago

450g of chromium(iii) sulfate reacts with excess potassium phosphate. How many grams of potassium sulfate will be produced? (ANS

ExtremeBDS [4]

Answer:

1597.959 g

Explanation:

Given Data:

Amount of Cr₂(SO₄)₃ = 450 g

Amount of potassium phosphate K₃PO₄ = in Excess

grams of potassium sulfate K₂SO₄= ?

Solution

The Reaction will be

Cr₂(SO₄)₃ + 2K₃PO₄ ----------> 3K₂SO₄ + 2CrPO₄

Information that we have from reaction

Cr₂(SO₄)₃ + 2K₃PO₄ ----------> 3K₂SO₄ + 2CrPO₄

1 mol 2 mol 3 mol

we come to know from the above reaction that

1 mole of chromium(iii) sulfate (Cr₂(SO₄)₃) react with 2 mole of potassium phosphate (K₃PO₄) to produce 3 mole of K₂SO₄

We also know that

molar mass of Cr₂(SO₄)₃ = 147 g/mol

molar mass of K₃PO₄ = 212 g/mol

molar mass of K₂SO₄ = 174 g/mol

if we represent mole in grams then

Cr₂(SO₄)₃ + 2K₃PO₄ ----------> 3K₂SO₄ + 2CrPO₄

1 mol (147 g/mol) 2 mol (212 g/mol) 3 mol (174g/mol)

So, Now we have the following details

Cr₂(SO₄)₃ + 2K₃PO₄ ----------> 3K₂SO₄ + 2CrPO₄

147 g 424 g 522 g

So,

we come to know that 147 g of Cr₂(SO₄)₃ combine with 424 g of 2K₃PO₄ produce 522 g of K₂SO₄

So now we calculate that how many grams of potassium sulfate will be produced

Apply unity formula

147 g of Cr₂(SO₄)₃ ≅ 522 g of K₂SO₄

450 g of Cr₂(SO₄)₃ ≅ ? g of K₂SO₄

by doing cross multiplication

g of K₂SO₄ =522 g x 450 g / 147 g

g of K₂SO₄ = 1597.959 g

So the write answer is 1597.959 g

***Note: By calculation it is obvious that the correct answer is 1597.959 g

8 0

3 years ago

I need to know the answer to that

Tresset [83]

im not sure which one to answer, and i can hardly see the text.

8 0

2 years ago