What information is required to calculate the average atomic mass of an element?

Stainless steel is an alloy of iron containing 5 percent nickel and 0.175 percent chromium. How many atoms of nickel are present

erica [24]

First you need to work out what mass of 84g of stainless steel is nickel, and because there's 5% you can simply divide by 20, giving 4.2g

For this you can use the equation $Moles= \frac{Mass}{Mr}$

The mass, as was worked out previously, is 4.2g
The Mr, which is found on the periodic table, is 28

Moles = $\frac{4.2}{28}$ = 0.15mol

1mol = 6.023 x $10^{23}$ atoms

So, 0.15mol = 0.15 x 6.023 x $10^{23}$ = 9.0345 x $10^{22}$ atoms

3 0

3 years ago

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Sulfur undergoes combustion to yield sulfur trioxide by the following reaction equation:

12345 [234]

Answer:

Therefore, the amount of heat produced by the reaction of 42.8 g S = (-5.2965 × 10²) kJ = (-5.2965 × 10⁵) J

Explanation:

Given reaction: 2S + 3O₂ → 2 SO₃

Given: The enthalpy of reaction: ΔH = - 792 kJ

Given mass of S: w₂ = 42.8 g, Molar mass of S: m = 32 g/mol

In the given reaction, the number of moles of S reacting: n = 2

As, Number of moles: $n = \frac{mass\: (w_{1})}{molar\: mass\: (m)}$

∴ mass of S in 2 moles of S: $w_{1} = n \times m = 2\: mol \times 32\: g/mol = 64\: g$

Given reaction: 2S + 3O₂ → 2 SO₃

In this reaction, the limiting reagent is S

⇒ 2 moles S produces (- 792 kJ) heat.

or, 64 g of S produces (- 792 kJ) heat.

∴ 42.8 g of S produces (x) amount of heat

⇒ The amount of heat produced by 42.8 g S:

$x = \frac{(- 792\: kJ) \times 42.8\: g}{64\: g} = (-529.65)\: kJ$

$\Rightarrow x = (-5.2965 \times 10^{2})\: kJ = (-5.2965 \times 10^{5})\: J$

$(\because 1 kJ = 10^{3} J)$

Therefore, the amount of heat produced by the reaction of 42.8 g S = (-5.2965 × 10²) kJ = (-5.2965 × 10⁵) J

8 0

3 years ago

I know the paper is blurry but can anyone explain any of the questions from 76-80?

Whitepunk [10]

Answer:try to make a good pic please I have ideas about the topic

3 0

3 years ago

What is the molality of a solution that is obtained by dissolving 2.922 g of NaCl into 1000.0 g of water if the molar mass of Na

never [62]

In order to find molarity, you must first find the number of moles that was dissolved.

Now, Moles = Mass ÷ Molar Mass

⇒ Moles of NaCl = 2.922 g ÷ 58.44 g/mol

= 0.05 moles

∴ the Molarity of the NaCl is 0.05 M [Option 1]

4 0

3 years ago

Conserving water can save money while protecting the environment. True or False

blagie [28]

Answer: The given statement is true.

Explanation:

Water is a natural resource present in the nature and it is very precious as life without it is impossible.

So, when we unnecessarily use water then it means we are wasting a natural resource that cannot be reproduced again by human beings.

Therefore, more we are able to conserve water more we can protect other human life's and environment also.

If there is shortage of water then its prices will go high and hence we need to pay more for it.

Thus, we can conclude that the statement conserving water can save money while protecting the environment, is true.

3 0

2 years ago

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