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3 years ago

NUMBERS 6-8 URGENT PLEASE

Chemistry

1 answer:

kodGreya [7K]3 years ago

5 0

Answer:

See explanation

Explanation:

9g of water contains : 9g/18 g/mol = 0.5 mole of water

1) 2 moles of hydrogen yields 2 moles of water

x moles of hydrogen yields 0.5 moles of water

x= 2 × 0.5/2 = 0.5 moles of hydrogen

Mass of hydrogen = 0.5 moles × 2 = 1 g of hydrogen

2) Number of moles of Al(OH)3 = 468 g/ 78 g/mol = 6 moles

2 moles of Al(OH)3 yields 3 moles of H2O

6 moles of Al(OH)3 yields 6 × 3/2 = 9 moles of H20

Mass of water =9 moles × 18 g/mol = 162 g of water

3) There are 13 oxygen atoms in the compound.

Mass of each oxygen atom = 16 g

Total mass of oxygen atoms = 13 × 16 = 208 g

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Answer:

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Explanation:

Based on the chemical equation:

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To solve this question we must convert the mass of CaCl2 to moles. Using the chemical equation we can find the moles of NaCl and its mass:

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Identify the catalyst in this reaction, explain how

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Question:

Sulfuric acid was once produced through the reaction of sulfur trioxide with water. Sulfur trioxide can form through the reaction of sulfur dioxide and oxygen gas. When nitrogen monoxide gas is added to the system, the reaction speeds up significantly because it proceeds through the following steps:

equations

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Answer:

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3 years ago

Read 2 more answers

determine the freezing point depression of a solution that contains 30.7 g glycerin (c3h8o3, molar mass

Blababa [14]

The freezing point depression of a solution containing 30.7 g of glycerin is calculated as -1.65°C

Equating :

It is given that,

Given mass of glycerin is = 30.7 grams (Solute)

Volume of water = 376 mL

$K_{f}$ or molar -freezing-depression point is = 1.86°C/m

Molar mass of glycerin = 92.09 g/mole

Now, to work out the value, the mass of water should be known. Thus, to calculate, the formula used will be:

Mass = Density X Volume

Mass = 1.0 g/mL X 376 mL

Mass = 376 g or 0.376 Kg

Using the formula of melting point depression, the equation becomes:

Δ $T_{f}$ = i × $K_{f}$ ×m

T⁰- $T_{s}$ = $i *K_{f} *\frac{mass of glycerin}{molar mass of glycerin * mass of water in kg}$

in which,

Δ $T_{f}$ = change in freezing point

Δ $T_{s}$ = freezing point of solution that has to be find

ΔT° = freezing point of water ()

Since, glycerin is a non-electrolyte, the Van't Hoff factor will be 1.

Substituting the values in the above equation:

0⁰C₋T $_{s}$ = 1 ×1.86°C/m × $\frac{30.7}{92.09g/mol * 0.376kg}$

$T_{s}$ = -1.65°C

Thus, the freezing point depression of a solution is -1.65°C

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Freezing point depression

Freezing point depression is a colligative property observed in solutions that results from the introduction of solute molecules to a solvent. The freezing points of solutions are all less than that of the pure solvent and is directly proportional to the molality of the solute

Is melting point elevation or depression?

Boiling point elevation is that the raising of a solvent's boiling point due to the addition of a solute. Similarly, melting point depression is the lowering of a solvent's freezing point due to the addition of a solute. In fact, because the boiling point of a solvent increases, its melting point decreases

Learn more about freezing point depression :

brainly.com/question/26525184

#SPJ4

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