Help me out anybody plz

Caffeine, a stimulant found in coffee, tea, and certain soft drinks, contains C, H, O, and N. Combustion of 1.000 mg of caffeine

Yuliya22 [10]

Answer:

194 g/mol

Explanation:

1) Content of C:

All the C atoms in the 1.000 mg of caffeine will be found in the 1.813 mg of CO₂.

Mass of C in 1.813 mg of CO₂

Since the atomic mass of C is 12.01 g/mol and the molar of of CO₂ is 44.01, there are 12 mg of C in 44 mg of CO₂ and you can set the proporton:

12.01 mg C / 44.01 mg CO₂ = x / 1.813 g CO₂

⇒ x = 1.813 × 12.01 / 44.01 g of C = 0.49475 mg of C

Number of moles of C

number of moles = mass in g / atomic mass = 0.49475×10⁻³ g / 12.01 g/mol = 4.1195×10⁻⁵ moles = 0.041195 milimol

2) Content of H

All the H atoms in the 1.000 mg of caffeine will be found in the 0.4639 mg of H₂O

Mass of H in 0.4639 mg of H₂O

Since the atomic mass of H is 1.008 g/mol and the molar of of H₂O is 18.015 g/mol, there are 2×1.008 mg of H in 18.015 mg of H₂O and you can set the proporton:

2×1.008 mg H / 18.015 mg H₂O = x / 0.4639 mg H₂O

⇒ x = 0.4639 mg H₂O × 2 × 1.008 mg H / 18.015 mg H₂O = 0.051913 mg H

Number of moles of H

number of moles = mass in g / atomic mass = 0.051913 ×10⁻³ g / 1.008 g/mol = 5.1501× 10⁻⁵ moles = 0.051501 milimol

3) Content of N

All the N atoms in the 1.000 mg of caffeine will be found in the 0.2885 mg of N₂

Mass of N in 0.2885 mg of N₂ is 0.2885 mg

Number of moles of N

number of moles = mass in g / atomic mass = 0.2885 ×10⁻³ g / 14.007 g/mol = 2.0597× 10⁻⁵ moles = 0.020597 milimol

4) Content of O

The mass of O is calculated by difference:

Mass of O = mass of sample - mass of C - mass of H - mass of N

Mass of O = 1.000 mg - 0.49475 mg C - 0.051913 mg H - 0.2885 mg N

Mass of O = 0.1648 mg

Moles of O = 0.1648 × 10 ⁻³ g / 15.999 g/mol = 1.0303×10⁻⁵ mol = 0.01030 milimol

5) Ratios

Divide every number of mililmoles by the smallest number of milimoles:

C: 0.041195 / 0.01030 = 4
H: 0.051501 / 0.01030 = 5
N: 0.020597 / 0.01030 = 2

O: 0.01030 / 0.01030 = 1

C: 4
H: 5
N: 2
O: 1

6) Empirical formula:

C₄H₅N₂O₁

7) Calculate the approximate mass of the empirical formula:

4 × 12 + 5 × 1 + 2 × 14 + 1 × 16 = 97 g/mol

So, since that number is not between 150 and 200 g/mol, multiply by 2: 97 × 2 = 194, which is between 150 and 200.

Thus, the estimate is 194 g/mol

7 0

3 years ago

..can someone answer these questions ive already posted this question 16 times and I dont have much points left so please anyone

noname [10]

Answer

A
D
D
A
B
A

This is what I got, but i'm mot sure if I'm right

7 0

3 years ago

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Use the formula F = (9/5)C + 32 to convert 35 degrees Celsius to Fahrenheit. Show your work.

torisob [31]

Answer:

95 °F

Explanation:

$F=\frac{9}{5} C + 32 \\ plug \: C = 35 \: in \: above \: equation\\ \\ F=\frac{9}{ \cancel5} \times \cancel {35 } \: \purple{\bold{ \: 7}}+ 32 \\F=9 \times 7 + 32 \\ F=63 + 32 \\ F=95$

4 0

3 years ago

What type of covalent bond is formed between amino acid molecules during protein synthesis? peptide bond electrovalent bond hydr

Brums [2.3K]

The type of covalent bond is formed between amino acid molecules during protein synthesis will be "peptide bond".

A peptide bond would be a sort of covalent link that connects an amino acid's carboxyl group to its amino group. Amino acids itself were comprised of atoms bonded together through covalent bonds.

Two atoms share an electron pair equally in a covalent link. Peptide (amide) but also disulfide links between amino acids, as well as C-C, C-O, and C-N bonds within amino acids, represent examples of significant covalent bonds.

Therefore, the type of covalent bond is formed between amino acid molecules during protein synthesis will be "peptide bond".

To know more about covalent bond

brainly.com/question/4463646

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8 0

2 years ago

What is another name for a condensation reaction? what is another name for a condensation reaction? water formation catabolism d

gregori [183]

Condensation is a chemical reaction in which two molecules are combined together and as a product formed a large molecule. There is also loss of small molecules in the condensation reaction. And mostly the functional groups combined in the reaction.
The other name for a condensation reaction is dehydration. As there is loss of molecule in condensation reaction, when that molecule is water it is said to be dehydration.

3 0

4 years ago

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