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4 years ago

The percent by mass of hydrogen in a compound that contains 2.45 g of hydrogen and 18.20 g of carbon is:

Chemistry

1 answer:

Anit [1.1K]4 years ago

4 0

Answer:

Total mass of the compound:=18.20+2.45

=20.65

Percentage by mass of hydrogen:=2.45÷20.65×100

=11.86%

Explanation:

Just follow the steps i have provided above

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how many milliliters of 0.200 m fecl3 are needed to react with an excess of na2s to produce 2.75 g of fe2s3 if the percent yield

Snezhnost [94]

Answer:

We need 203 mL of FeCl3

Explanation:

Step 1: Data given

molarity FeCl3 = 0.200 M

Mass of Fe2S3 = 2.75 grams

Percent yield = 65.0 %

Step 2: The balanced equation

3 Na₂S(aq) + 2 FeCl₃(aq) → Fe₂S₃(s) + 6 NaCl(aq)

Step 3: Calculate moles Fe2S3

Moles Fe2S3 = mass Fe2S3 / molar mass Fe2S3

Moles Fe2S3 = 2.75 grams / 207.9 g/mol

Moles Fe2S3 = 0.0132 moles

Step 4: Calculate theoretical yield

65.0 % = 0.65 = actual yield/ theoretical yield

theoretical yield = actual yield / 0.65

theoretical yield = 0.0132 moles /0.65

theoretical yield = 0.0203 moles Fe2S3

Step 5: Calculate moles FeCl3

For 1 mol Fe2S3 and 6 mol NaCl we need 3 moles Na2S and 2 moles FeCl3

For 0.0203 moles Fe2S3 we need 2*0.0203 = 0.0406 moles FeCl3

Step 6: Calculate volume

Molarity = moles / volume

Volume = moles / molarity

Volume = 0.0406 moles / 0.200 M

Volume = 0.203 L = 203 mL

We need 203 mL of FeCl3

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4 years ago

State two uses of periscope

adoni [48]

Uses Of Periscope
It is used in submarines to determine the distance of a torpedo and helps in deciding the right time for the attack.
It is used in a nuclear reactor to observe the chemical reactions that are taking place.
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3 years ago

Dominique goes to the doctor for bone aches. The doctor tells him

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Answer:

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Explanation:

Our body creates vitamin D from direct sunlight on our skin when we're outdoors.

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3 years ago

Ammonia and copper(II) oxide react to form solid copper, water and nitrogen gas. What are the coefficients for the balanced chem

motikmotik

Answer:

Explanation:

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3 years ago

Read 2 more answers

Convert 3.01€22 molecules of O²(a) mole of O²) ,volume at S.T.P,no of Oxygen atom. (d) mass

Marat540 [252]

Answer:

a )0.05 moles of O₂

b) 1.1207 dm³

c) 0.3× 10²³ atoms of oxygen

d) 1.6 g

Explanation:

Given data:

Number of molecules of O₂ = 3.01 × 10²² molecules

Number of moles of O₂ = ?

Volume of oxygen at ATP = ?

Number of oxygen atoms = ?

Mass of oxygen = ?

Solution:

The given problem will solve by using Avogadro number.

"It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance". The number 6.022 × 10²³ is called Avogadro number.

Moles of oxygen:

1 mole = 6.022 × 10²³ molecules

3.01 × 10²² molecules × 1 mol / 6.022 × 10²³ molecules

0.05 moles of O₂

Number of atoms of oxygen:

1 mole = 6.022 × 10²³ atoms

0.05 mol × 6.022 × 10²³ atoms /1 mol

0.3× 10²³ atoms of oxygen

Volume of oxygen:

1 mole of oxygen at STP occupy 22.414 dm³

0.05 mol × 22.414 dm³ / 1mol

1.1207 dm³

Mass of oxygen:

Mass = number of moles × molar mass

Mass = 0.05 mol × 32 g/mol

Mass = 1.6 g

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3 years ago