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3 years ago

What is a molecular formula?

1 answer:

5 0

The symbolic representation of its compound and its composition.

or a chemical formula that indicates the kinds of atoms and the number of each kind in a molecule of a compound.
ANSWER IS B

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if I have 22.1 grams of CO2 gas at -188 degrees Celsius and 165 ml what is the pressure of the gas in kPa

Harman [31]

Answer:

P = 2.145kPa

Explanation:

Mass = 22.1g

Molar mass of CO2 = 44g/mol

Vol = 165mL = 0.165L

T = -188°C = (-188 + 273.15)K = 85.15K

R = 8.314J/mol.K

From ideal gas equation,

PV = nRT

P = pressure of the ideal gas

V = volume the gas occupies

n = number of moles if the gas

R = ideal gas constant

T = temperature of the gas

n = number of moles

n = mass / molar mass

n = 22.1 / 44 = 0.50moles

PV = nRT

P = nRT/ V

P = (0.5 × 8.314 × 85.15) / 0.165

P = 2145.26Pa = 2.145kPa

Pressure of the gas is 2.145kPa

6 0

3 years ago

An analytical chemist is titrating of a solution of propionic acid with a solution of 224.9 ml of a 0.6100M solution of propioni

Svetllana [295]

Answer: The pH of acid solution is 4.58

Explanation:

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}$ .....(1)

For KOH:

Molarity of KOH solution = 1.1000 M

Volume of solution = 41.04 mL

Putting values in equation 1, we get:

$1.1000M=\frac{\text{Moles of KOH}\times 1000}{41.04}\\\\\text{Moles of KOH}=\frac{1.1000\times 41.04}{1000}=0.04514mol$

For propanoic acid:

Molarity of propanoic acid solution = 0.6100 M

Volume of solution = 224.9 mL

Putting values in equation 1, we get:

$0.6100M=\frac{\text{Moles of propanoic acid}\times 1000}{224.9}\\\\\text{Moles of propanoic acid}=\frac{0.6100\times 224.9}{1000}=0.1372mol$

The chemical reaction for propanoic acid and KOH follows the equation:

$C_2H_5COOH+KOH\rightarrow C_2H_5COOK+H_2O$

Initial: 0.1372 0.04514

Final: 0.09206 - 0.04514

Total volume of solution = [224.9 + 41.04] mL = 265.94 mL = 0.26594 L (Conversion factor: 1 L = 1000 mL)

To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:

$pH=pK_a+\log(\frac{[\text{salt}]}{[acid]})$

$pH=pK_a+\log(\frac{[C_2H_5COOK]}{[C_2H_5COOH]})$

We are given:

$pK_a$ = negative logarithm of acid dissociation constant of propanoic acid = 4.89

$[C_2H_5COOK]=\frac{0.04514}{0.26594}$

$[C_2H_5COOH]=\frac{0.09206}{0.26594}$

pH = ?

Putting values in above equation, we get:

$pH=4.89+\log(\frac{(0.04514/0.26594)}{(0.09206/0.26594)})\\\\pH=4.58$

Hence, the pH of acid solution is 4.58

7 0

4 years ago

Where do you write salt and suger why

Rashid [163]

Answer:

here: "salt and sugar"

Explanation:

I dunno, looks pretty, gives 5 points. even tough any context is missing

but seriously:

salt and sugar look the same. just someone with a split personality

7 0

3 years ago

How are carrot, an amoeba, and a bacterium alike

sineoko [7]

They should all be eukaryotic.

4 0

4 years ago

Read 2 more answers

An aqueous solution is 40.0 % by mass hydrochloric acid, HCl, and has a density of 1.20 g/mL. The mole fraction of hydrochloric

vivado [14]

Answer:

The molar concentration of HCl in the aqueous solution is 0.0131 mol/dm3

Explanation:

To get the molar concentration of a solution we will use the formula:

Molar concentration = mass of HCl/ molar mass of HCl

Mass of HCl in the aqueous solution will be 40% of the total mass of the solution.

We can extract the mass of the solution from its density which is 1.2g/mL

We will further perform our analysis by considering only 1 ml of this aqueous solution.

The mass of the substance present in this solution is 1.2g.

The mass of HCl Present is 40% of 1.2 = 0.48 g.

The molar mass of HCl can be obtained from standard tables or by adding the masses of Hydrogen (1 g) and Chlorine (35.46 g) = 36.46g/mol

Therefore, the molar concentration of HCl in the aqueous solution is 0.48/36.46 = 0.0131 mol/dm3

7 0

3 years ago