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3 years ago

Giving brainliest if correct!! please help someone out?

Chemistry

1 answer:

Stels [109]3 years ago

5 0

Answer:

protons: 36

neutrons:48

electrons:36

Explanation:

the number of protons in an element is = to the atomic # (36)

the number of neutrons is the atomic mass - atomic # (84-36=48)

In a neutral charged element the # of protons = # of electrons

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If you obtain 3.0 grams of aspirin from an experiment that could make no more than 3.14 grams, what is the percent yield?

Masteriza [31]

Answer:

96%

Explanation:

To find the percent yield, we can use this equation

$\frac{Actual}{Theoretical} *100$

The actual yield of aspirin is 3.0 and the theoretical is 3.14 in this case, so just plug the numbers in.

$\frac{3.0}{3.14} *100\\\\ =96$

Thus the percent yield is 96%

;)

3 0

3 years ago

1. What do gram-formula mass and atomic mass have in common? How are they different?

elixir [45]

Because they do not have the same qualities therefore they are different

3 0

3 years ago

A sample of calcium phosphate was found to have a mass of 125.3 g. How many molecules were contained in the sample?

Viktor [21]

The answer for the following problem is mentioned below.

<u><em>Therefore number of molecules(N) present in the calcium phosphate sample are 19.3 × 10^23 molecules.</em></u>

Explanation:

Given:

mass of calcium phosphate ( $Ca_{3}(PO_{4} )_{2}$ ) = 125.3 grams

We know;

molar mass of calcium phosphate ( $Ca_{3}(PO_{4} )_{2}$ ) = (40×3) + 3 (31 +(4×16))

molar mass of calcium phosphate ( $Ca_{3}(PO_{4} )_{2}$ ) = 120 + 3(95)

molar mass of calcium phosphate ( $Ca_{3}(PO_{4} )_{2}$ ) = 120 +285 = 405 grams

<em>We also know;</em>

No of molecules at STP conditions( $N_{A}$ ) = 6.023 × 10^23 molecules

To solve:

no of molecules present in the sample(N)

We know;

$\frac{m}{M} =\frac{N} }{}$ N÷ $N_{A}$

$\frac{405}{125.3}$ = $\frac{N}{6.023*10^23}$

N =(405×6.023 × 10^23) ÷ 125.3

N = 19.3 × 10^23 molecules

<u><em>Therefore number of molecules(N) present in the calcium phosphate sample are 19.3 × 10^23 molecules</em></u>

3 0

3 years ago

A 3.0 g sample of a gas occupies a volume of 1.00L at 100C and 740 torr pressure. The molecular weight of the

SOVA2 [1]

Answer:

94.2 g/mol

Explanation:

Ideal Gases Law can useful to solve this

P . V = n . R . T

We need to make some conversions

740 Torr . 1 atm/ 760 Torr = 0.974 atm

100°C + 273 = 373K

Let's replace the values

0.974 atm . 1 L = n . 0.082 L.atm/ mol.K . 373K

n will determine the number of moles

(0.974 atm . 1 L) / (0.082 L.atm/ mol.K . 373K)

n = 0.032 moles

This amount is the weigh for 3 g of gas. How many grams does 1 mol weighs?

Molecular weight → g/mol → 3 g/0.032 moles = 94.2 g/mol

3 0

3 years ago

Calculate the number of moles in the following: 2.8 X 10^24 atoms of Cl2

vova2212 [387]

Answer:

<h3>The answer is 4.65 moles</h3>

Explanation:

To find the number of moles given it's number of entities we use the formula

$n = \frac{N}{L} \\$

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question

N = 2.8 × 10²⁴ atoms of Cl2

So we have

$n = \frac{2.8 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 4.65116279069...$

We have the final answer as

<h3>4.65 moles</h3>

Hope this helps you

7 0

3 years ago