All categories

2 years ago

PLZ HELP ASAP PLATO!!! BRAINLIEST TO WHOEVER ANSWERS CORRECTLY!!!

Chemistry

1 answer:

katen-ka-za [31]2 years ago

3 0

Explanation:

a. 0.0093

Number of significant figures = 2

All zero’s preceding the first integers are never significant

b. 120.9

Number of significant figures = 4

All zero’s between integers are always significant.

c. 1,000

Number of significant figures = 1

All zeroes used solely for spacing the decimal point are not significant.

d. 1.008

Number of significant figures = 4

All zero’s between integers are always significant.

All zero’s after the decimal point are always significant.

e. 670

Number of significant figures = 2

All zeroes used solely for spacing the decimal point are not significant.

f. 0.184

Number of significant figures = 3

All zero’s after the decimal point are always significant.

g. 1.30

Number of significant figures = 3

All zero’s after the decimal point are always significant.

You might be interested in

Which of these was not proposed by john dalton in 1805?

wel

Answer:

Atoms are made of protons, neutrons and electrons.

Explanation:

The Dalton's atomic theory was an early attempt at describing the properties of atoms. It stipulated that atoms were the smallest indivisible particle of a substance. Chemical reactions occur as a result of a combination or separation of atoms. Atoms of the same element are exactly alike and differ from atoms of other elements. Atoms can neither be created nor destroyed.

As time went on, modern scientific evidence began to modify the original postulates of the Dalton's atomic theory. It was not postulated in 1805 that atoms were composed of subatomic particles; electrons, neutrons and protons. Dalton's theory held the atom to be 'indivisible'. However in 1897, JJ Thompson discovered the electron. Subsequently, the proton and neutrons were discovered. This shows that the atom in itself consisted of even smaller particles.

3 0

2 years ago

Choose two different particles found in the air. Explain how they are different and how they are the same

BARSIC [14]

Answer:

Dust and smoke.

Explanation:

Dust and smoke are two different particles present in the air. Dust and smoke are different from one another due to their origin. Smoke formed from burning of materials while dust refers to the soil particles lifted by the wind due to their light weight. Dust and smoke are similar to each other due to their small in size, infinite number means uncountable and light weight.

6 0

2 years ago

Which of the following procedures demonstrates repetition? A. Jeremiah measures the mass of five different strips of metal. He p

lara31 [8.8K]

The answer is C bc i did it already.

7 0

2 years ago

Read 2 more answers

In Part A, you found the amount of product (1.80 mol P2O5 ) formed from the given amount of phosphorus and excess oxygen. In Par

Finger [1]

First step is to balance the reaction equation. Hence we get P4 + 5 O2 => 2 P2O5

Second, we calculate the amounts we start with

P4: 112 g = 112 g/ 124 g/mol – 0.903 mol

O2: 112 g = 112 g / 32 g/mol = 3.5 mol

Lastly, we calculate the amount of P2O5 produced.

2.5 mol of O2 will react with 0.7 mol of P2O5 to produce 1.4 mol of P2O5.

This is 1.4 * (31*2 + 16*5) = 198.8 g

3 0

2 years ago

Exactly 56 grams of iron is mixed with 156 grams of oxygen. The elements are heated and they react. What best describes which re

Mars2501 [29]

Answer:

Explanation:

The chemical expression for the reaction between iron and oxygen is:

4Fe(s) + 3O₂ (g) $\to$ 2Fe₂O₃ (s)

The number of moles of Fe = mass of Fe/ molecular mass of Fe

The number of moles of Fe = 56 g/ 55.845 g/mol

The number of moles of Fe = 1.002 moles of Fe

The number of moles of oxygen = mass of oxygen/ molecular mass of oxygen

The number of moles of oxygen = 156 g /32 g/mol

The number of moles of oxygen = 4.875 moles of oxygen

Assume that Fe is the limiting reactant, the number of Fe₂O₃ can be calculated as:

moles of Fe₂O₃ = 1.002 mole of Fe × 2 moles of Fe₂O₃/ 4 moles of Fe

moles of Fe₂O₃ = 0.501 mole of Fe₂O₃

Assume that O₂ is the limiting factor, the number of Fe₂O₃ is:

moles of Fe₂O₃ = 4.875 moles of O₂ × 2 moles of Fe₂O₃/ 3 moles of O₂

moles of Fe₂O₃ = 3.25 mole of Fe₂O₃

Thus, after the reaction is complete, Fe and O₂ contain different moles of Fe₂O₃. Only Fe gets consumed in the reaction and it is the limiting factor.

8 0

1 year ago