Chemistry, 26.01.2021 22:20 zoeyandblaze

The equation representing the formation of water from oxygen and hydrogen is: 2H2 + O2 > 2H2O In this reaction 32 grams of oxygen react with 4 grams of hydrogen to form two molecules of water. The Law of Conservation of Matter (mass) is supported by this reaction because?

A) 2 hydrogen atoms react with 2 oxygen atoms to form 2 water molecules

B) the volume of the oxygen and hydrogen will equal the volume of the water

C) 32 grams of oxygen and 4 grams of hydrogen will produce 36 grams of water

D) the size of the hydrogen and oxygen atoms and the water molecules will be equal

Answers: 3

Show answers

Answers

Answer from: Quest

the missing options are :

(1) lower boiling point and a lower freezing point(2) lower boiling point and a higher freezing point(3) higher boiling point and a lower freezing point(4) higher boiling point and a higher freezing point

answer : the correct answer is option (3) higher boiling point and a lower freezing point

explanation :

when a non volatile solute is added to a solvent like water, it results in elevation of boiling point.

let us find the increase in boiling point of water when cacl₂ is added to water to make a solution of 1 m

step 1 : find molality of the solution

let us assume we have 1 l of solution.

$m = \frac{moles (solute)}{l ( solution)}$

$1 m = \frac{moles (cacl_{2})}{1 l }= 1 mol cacl_{2}$

let us convert this to grams of cacl₂.

molar mass of cacl2 is 111 g/mol

grams of cacl₂ = $1 mol \times \frac{111g}{mol} = 111 g cacl_{2}$

mass of solute = 111 g

assuming density of solution same as water which is 1g/ml we have ,

mass of solution = density * volume

mass of solution = $\frac{1g}{ml} \times 1000 ml = 1000 g$

mass of solution = mass of solvent + mass of solute

mass of solute = 1000g - 111g

mass of solute 889 g = 0.889 kg

the molality of the solution can be calculated as

$molality = \frac{mol (solute)}{kg ( solvent)}$

$molality = \frac{1mol}{0.889kg}$

molality = 1.12 m

step 2 : find boiling point elevation.

the elevation in boiling point is calculated as

$\bigtriangleup t_{b} = i \times k_{b} \times m$

here δtb = boiling point elevation

i = vant hoff factor which is the number of ions formed by the solute .

cacl₂ dissociates as $cacl_{2} \rightarrow ca^{2+} + 2 cl^{-}$

it forms 3 ions . therefore,

i = 3

m = molality which is 1.12 m

kb is constant for a given solvent. for water it is 0.512

$\bigtriangleup t_{b} = 3 \times 0.512 \times 1.12$

$\bigtriangleup t_{b} = 1.7$

the boiling point of water increases by 1.7 °c

step 3: find freezing point depression.

when a non volatile solute is added to water, it results in decrease in freezing point.

the formula to find freezing point depression is

$\bigtriangleup t_{f} = i \times k_{f} \times m$

kf is constant for water and its value is 1.86

$\bigtriangleup t_{f} = 3 \times 1.86 \times 1.12$

$\bigtriangleup t_{f} = 6.2$

the freezing point of water decreases by 6.2 °c

therefore we can say that, the solution will have a higher boiling point and a lower freezing point

Answer from: Quest

A(apex

Answer from: Quest

The fraction of an original sample of tritium that remains unchanged after 24.62 years is 1/4. if you need the percentage it is 25%

Answer from: Quest

0.4 j/gcplug in known variables to specific heat equation

Another question on Chemistry

Chemistry, 22.06.2019 06:00

Why is permeable soil best for plants that need a lot of drainage?

Answers: 1

Answer

Chemistry, 22.06.2019 12:10

|using the periodic tablewarm-upuse the periodic table in the tools bar to answer the following questions.what elemental classification does oxygen belongto? done

Answers: 3

Answer

Chemistry, 22.06.2019 19:40

What causes different colors to appear in the sky? the absorption of light by air molecules the reflection of light by bodies of water the greenhouse effect in earth's atmosphere the scattering and reflection of light by dust particles

Answers: 2

Answer

Chemistry, 23.06.2019 08:30

Plz a person walks 1 mile every day for exercise, leaving her front porch at 9 am and returning to her front porch at 9: 25 am what was the total displacement of her daily walk a. 1 mile b. 0 c. 25 min d. none of the above

Answers: 2

Answer

You know the right answer?

The equation representing the formation of water from oxygen and hydrogen is: 2H2 + O2 > 2H2O...

Questions