All categories

2 years ago

How many moles of iron in a sample that contains 7.91×10^23 atoms of iron?

Chemistry

1 answer:

vazorg [7]2 years ago

5 0

Answer: 1.31

Explanation:

No.of moles = given no.of atoms/Avagadro number

= 7.91×10^23 / 6.022 x 10^23

= 1.31

therefore, no.of moles = 1.31

Hope it helped u,

pls mark as the brainliest

^_^

You might be interested in

Hi pls help pls pls. this is due at 11:59 help

Sveta_85 [38]

Answer:

mass of salt 6.72g

Explanation:

mass of the combine mass with salt- mass of the empty beaker

36.176g−29.456g=6.72g

7 0

7 months ago

Calculate the mass of magnesium carbonate ( MgCO3), in grams, required to produce 110.0 g of carbon dioxide using the following

bearhunter [10]

Answer:

$210.7~g~MgCO_3$

Explanation:

We have to start with the reaction:

$MgCO_3~->~MgO~+~CO_2$

We have the same amount of atoms on both sides, so, we can continue. The next step is to find the number of moles that we have in the 110.0 g of carbon dioxide, to this, we have to know the atomic mass of each atom:

C: 12 g/mol

O: 16 g/mol

Mg: 23.3 g/mol

If we take into account the number of atoms in the formula, we can calculate the molar mass of carbon dioxide:

$(12*1)+(16*2)=44~g/mol$

In other words: $1~mol~CO_2=~44~g~CO_2$ . With this in mind, we can calculate the moles:

$110~g~CO_2\frac{1~mol~CO_2}{44~g~CO_2}=25~mol~CO_2$

Now, the molar ratio between carbon dioxide and magnesium carbonate is 1:1, so:

$2.5~mol~CO_2=2.5~mol~MgCO_3$

With the molar mass of $MgCO_3$ ( $(23.3*1)+(12*1)+(16*3)=84.3~g/mol$ . With this in mind, we can calculate the grams of magnesium carbonate:

$2.5~mol~MgCO_3\frac{84.3~g~MgCO_3}{1~mol~MgCO_3}=210.7~g~MgCO_3$

I hope it helps!

8 0

2 years ago

Which one is a true statement about endothermic reactions? a: More heat is given off than is put into the reaction. b :The react

Setler [38]

A because it gets hot

7 0

2 years ago

Which of the following describes the location and energy of all the valence electrons

Nastasia [14]

Answer:

1s22s22p63s23p4

Explanation:

Sulfur is located in the p block and has 6 valence electrons (the 2 exponent on the 3s and the 4 exponent on the 3p add up to 6)

4 0

2 years ago

Is it true or false a population is all of the plants and animals that live within a ecosystem

Mars2501 [29]

The correct answer would have to be true

4 0

2 years ago

Read 2 more answers