A sample of sugar (C12H22O11) contains 1.505 × 1023 molecules of sugar. How many moles of sugar are present in the sample?

5.943x10^24 molecules of H3PO4 will need how many grams of Mg(OH)2 in the reaction below? 3 Mg(OH)2 + 2 H3PO4 -------> 1 Mg3(

professor190 [17]

Answer:

Mass of Mg(OH)₂ required for the reaction = 863.13 g

Explanation:

3Mg(OH)₂ + 2H₃PO₄ -------> Mg₃(PO₄)₂ + 6H₂O

(5.943 x 10²⁴) molecules of H₃PO₄ is available fore reaction. Mass of Mg(OH)₂ required for reaction.

According to Avogadro's theory, 1 mole of all substances contain (6.022 × 10²³) molecules.

This can allow us find the number of moles that (5.943 x 10²⁴) molecules of H₃PO₄ represents.

1 mole = (6.022 × 10²³) molecules.

x mole = (5.943 x 10²⁴) molecules

x = (5.943 x 10²⁴) ÷ (6.022 × 10²³)

x = 9.87 moles

From the stoichiometric balance of the reaction,

2 moles of H₃PO₄ reacts with 3 moles of Mg(OH)₂

9.87 moles of H₃PO₄ will react with y moles of Mg(OH)₂

y = (3×9.87)/2 = 14.80 moles

So, 14.8 moles of Mg(OH)₂ is required for this reaction. We them convert this to mass

Mass = (number of moles) × Molar mass

Molar mass of Mg(OH)₂ = 58.3197 g/mol

Mass of Mg(OH)₂ required for the reaction

= 14.8 × 58.3197 = 863.13 g

Hope this Helps!!!

5 0

4 years ago

Read 2 more answers

A student wants to remove the salt from a mixture of sand and salt in order to get only pure sand. He adds water to the mixture.

raketka [301]

Answer:

Here is one way: Add water to the mixture. Only the sugar dissolves. This is a physical change.

Explanation:

The sugar would dissolve in water. You could then pour off the solution and wash the remaining sand with a bit more water. Heat the water to evaporate it from the sugar, and the two are separated.

5 0

3 years ago

Read 2 more answers

What happens to the number of valence electrons as you move from element 1 to element 18 on the periodic table?

BARSIC [14]

Answer:

B

Explanation:

the group number is=valence electrons. element 1 is in group 1 element 18 is in group 8. 1<8

6 0

3 years ago

Read 2 more answers

Which type of reaction forms water from hydrogen and oxygen atoms?

Cloud [144]

I believe it was decomposition reaction

7 0

3 years ago

A chemist prepares a solution of sodium carbonate by measuring out of sodium carbonate into a volumetric flask and filling the f

Vadim26 [7]

Answer:

The correct answer will be " $9.45\times 10^{-5} \ mol/L$ ".

Explanation:

We have:

Moles of solute (Na₂Co₃) = $18.9 \mu \ mol$

= $18.9\times 10^{-6}$

$1 \mu \ mol$ = $10^{-6} \ mol$

Now,

The volume of the solution will be:

⇒ $0.200 \ L$

∴ ${1 \ mL=0.001 \ L}$

The formula to find the concentration will be:

⇒ $Concentration = \frac{moles \ of \ solute \ (mol)}{Volume \ of \ solution \ (L)}$

On substituting the given values, we get

⇒ $=\frac{18.9\times 10^{-6}}{0.200}$

⇒ $=9.45\times 10^{-5} \ mol/L$

8 0

3 years ago