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4 years ago

Thomson's experiments were significant in that they questioned

Chemistry

2 answers:

castortr0y [4]4 years ago

8 0

The answer is letter D

Vlad [161]4 years ago

6 0

Answer:

The correct answer is option B.

Explanation:

J.J Thomson was an English physicist who had given the plum pudding model of the atom in 1904. In which he described about the existence of two subatomic particles which are protons (positive particles) and electrons (negative particles).

In his model atom was considered to be a pudding or bed of positive charge in which negative particles are present same as as plum on the pudding.

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What is the weight of:

Dafna11 [192]

Answer:

Oxygen = 15.999 g/mol

Iron = 3 × 55.845 = 167.535 g/mol

CaCO3 = 20 × 100.0869 = 2001.738 g/mol

8 0

3 years ago

Independent variable

katrin [286]

Answer:

Independent variable

aluminium ball

6 0

3 years ago

A 0.98 gram sample of a volatile liquid was heated to 348 k. the gas occupied 265 ml of space at a pressure of 0.95 atm. what is

arlik [135]

Answer:

The molecular weight is $Z = 111.2 \ g/mol$

Explanation:

From the question we are told that

The mass of the sample is $m = 0.98 \ g$

The temperature is $T = 348 K$

The volume which the gas occupied is $V = 265 \ ml = 265 *10^{-3} L$

The pressure is $P = 0.95 \ atm$

Generally from the ideal gas equation we have that

$PV = n RT$

Here n is the number of moles of the gas while the R is the gas constant with value $R = 0.0821 \ atm \cdot L \cdot mol^{-1} \cdot K^{-1}$

$n = \frac{PV}{ RT}$

=> $n = \frac{ 0.95 * 265 *10^{-3} }{ 0.0821 * 348}$

=> $n = 0.00881 \ mol$

Generally the molecular weight is mathematically represented as

$Z = \frac{m}{n}$

=> $Z = \frac{0.98 }{0.00881}$

=> $Z = 111.2 \ g/mol$

8 0

3 years ago

1. Oxygen was discovered by Joseph Priestley in 1774 when he heated mercury (II) oxide, HgO, to decompose it to form its constit

Tomtit [17]

Answer:

1. 7.81 moles HgO

2. n = mass/molar mass = (4000 g)/(159.69 g/mol) = 25.05 mol.

Explanation:

How many moles of mercury (II) oxide are needed to produce 125 g of oxygen?

2HgO ==> 2Hg + O2

125 g O2 x 1 mol O2/32 g x 2 mol HgO / mol O2 = 7.81 moles HgO

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If 4000 g of Fe2O3 is available to react, how many moles of CO are needed?

The no. of moles of CO are needed = 75.15 mol.

Fe₂O₃ + 3CO → 2Fe + 3CO₂,

It is clear that 1 mol of Fe₂O₃ reacts with 3 mol of CO to produce 2 mol of Fe and 3 mol of CO₂.

If 4.00 kg Fe₂O₃ are available to react, how many moles of CO are needed?

We need to calculate the no. of moles of 4.00 kg Fe₂O₃:

n = mass/molar mass = (4000 g)/(159.69 g/mol) = 25.05 mol.

Using cross multiplication:

1 mol of Fe₂O₃ need → 3 mol of CO to react completely, from stichiometry.

25.05 mol of Fe₂O₃ need → ??? mol of CO to react completely.

The no. of moles of CO are needed = (3 mol)(25.05 mol)/(1 mol) = 75.15 mol.

6 0

3 years ago

Given the number of a substance , how do you solve for the number of a moles of a substance

chubhunter [2.5K]

Given the number of a substance, we can solve the number of moles by using a conversion factor that would relate the number of a substance to the number of moles. In any case, Avogadro's number would be used. It <span>represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles. For example, we are given 1.23 x 10^24 atoms of a substance converting it to moles we do as follows:

</span>1.23 x 10^24 atoms ( 1 mol / 6.022x10^23 atoms ) = 2.04 moles

5 0

3 years ago