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3 years ago

What percentage of the mass of a carbon-12 atom is

Chemistry

1 answer:

Lynna [10]3 years ago

7 0

Answer:

% of mass of electrons in C = 0.0272

Explanation:

Atomic no. of carbon = 6

So, no. of electron = 6

Mass of an electron = $\frac{1}{1836} amu$

Mass of 6 electrons = $6 \times \frac{1}{1836} = 0.003268 amu$

Mass of C = 12.0107 u

% of mass of electrons in C = $\frac{Mass\ of\ all\ electrons}{Mass\ of\ C}\times 100$

% of mass of electrons in C = $\frac{0.003268}{12.0107}\times 100=0.0272 \%$

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A solution has a higher boiling point than its associated pure solvent does.

marta [7]

Answer:

4 boiling point elevation

7 0

3 years ago

What is the theoretical yield of fluorenone if you oxidize 175 mg of fluorene?

My name is Ann [436]

Answer:

602 mg of CO₂ and 94.8 mg of H₂O

Explanation:

The yield is measured by the amount of each product produced by the reaction.

The chemical formula of fluorene is C₁₃H₁₀, and its molar mass is 166.223 g/mol.

The oxidation, also know as combustion, of this hydrocarbon is represented by the following balanced chemical equation:

$2C_{13}H_{10}+31O_2\rightarrow 26CO_2+10H_2O$

To calculate the yield follow these steps:

1. Mole ratio

$2molC_{13}H_{10}:31molO_2:26molCO_2:10molH_2O$

2. Convert 175mg of fluorene to number of moles

$175mg/times 1g/1,000mg=0.175g$

Number of moles = mass in grams / molar mass

$\text{number of moles}=0.175g/166.223g/mol=0.0010528mol$

3. Set a proportion for each product of the reaction

a) For CO₂

i) number of moles

$2molC_{10}H_{13}/26molCO_2=0.0010528molC_{10}H{13}/x$

$x=0.0010528molC_{10}H_{13}\times 26molCO_2/2molC_{10}H_{13}=0.013686molCO_2$

ii) mass in grams

The molar mass of CO₂ is 44.01g/mol

mass = number of moles × molar mass

mass = 0.013686 moles × 44.01 g/mol = 0.602 g = 602mg

b) For H₂O

i) number of moles

$0.0010528molC_{10}H_{13}\times10molH_2O/2molC_{10}H_{13}=0.00526molH_2O$

ii) mass in grams

The molar mass of H₂O is 18.015g/mol

mass = number of moles × molar mass

mass = 0.00526 moles × 18.015 g/mol = 0.0948mg = 94.8 mg

4 0

3 years ago

A solution is made by adding 29.1 mL of concentrated perchloric acid ( 70.5 wt% , density 1.67 g/mL ) to some water in a volumet

Lera25 [3.4K]

Answer:

The concentration of the solution is 1.364 molar.

Explanation:

Volume of perchloric acid = 29.1 mL

Mass of the solution = m

Density of the solution = 1.67 g/mL

$m=1.67 g/mL\times 29.1 mL=48.597 g$

Percentage of perchloric acid in 48.597 solution :70.5 %

Mass of perchloric acid in 48.597 solution :

= $\frac{70.5}{100}\times 48.597 = 34.261 g$

Moles of perchloric acid = $\frac{34.261 g}{100.46 g/mol}=0.3410 mol$

In 29.1 mL of solution water is added and volume was changed to 250 mL.

So, volume of the final solution = 250 mL = 0.250 L (1 mL = 0.001 L)

$Molarity=\frac{Moles}{Volume (L)}$

$=\frac{0.3410 mol}{0.250 L}=1.364 M$

The concentration of the solution is 1.364 molar.

6 0

3 years ago

57. A recipe for s'mores calls for 2 graham crackers, 2 chocolate pieces and 1 marshmallow. If I

geniusboy [140]

Answer:Noble gases:

are highly reactive.

react only with other gases.

do not appear in the periodic table.

are not very reactive with other elements.

Explanation:Noble gases:

are highly reactive.

react only with other gases.

do not appear in the periodic table.

are not very reactive with other elements.

5 0

2 years ago

Calculate the potential energy of a 25kg ball sitting 25m high

Mariulka [41]

The answer is 6,125. To get this you multiply both by 9.8

8 0

3 years ago