Which type of galaxy contains mostly new stars because it has lots of dust and gas

Researchers used a combustion method to analyze a compound used as an antiknock additive in gasoline. A 9.394 mg sample of the c

LuckyWell [14K]

Answer:

The percent composition of the compound is 90.5 % C and 9.5 % H

Explanation:

Step 1: Data given

Mass of compound = 9.394 mg

Mass of CO2 yielded = 31.154 mg

Mass of H2O yielded = 7.977 mg

Molar mass of CO2 = 44.01 g/mol

Molar mass of H2O = 18.02 g/mol

Step 2: Calculate moles CO2

moles of CO2 = (0.031154 g / 44.01 g/mol) = 7.08 * 10^-4 mol CO2

Step 3: Calculate moles C

moles of C = moles of CO2 * (1 mol C / 1 mol CO2)

moles of C = 7.08 * 10^-4 mol

Step 4: Calculate moles H2O

moles of H2O = (0.007977 g / 18.02 g/mol) = 4.43 * 10^-4 mol H2O

Step 5: Calculate moles of H

moles of H = moles of H2O * (2 mol H / 1 mol H2O)

moles of H = 4.43* 10^-4 *2 = 8.86 * 10^-4 mol H

Step 6: Calculate mass of C

mass C = moles C * molar mass C

mass C = 7.08 * 10^-4 mol*12.01 g/mol

mass C = 0.0085 grams

Step 7: Calculate mass of H

mass H = moles H * molar mass H

mass H = 8.86 * 10^-4 mol*1.01 g/mol

mass H = 0.000894 grams

Step 8: Calculate total mass of compound =

0.0085 grams + 0.000894 grams = 0.009394 grams = 9.394 mg

Step 9: Calculate the percent composition:

% C = (8.50 mg / 9.394 mg) x 100 = 90.5%

% H = (0.894 mg / 9.394 mg) x 100 = 9.5%

The percent composition of the compound is 90.5 % C and 9.5 % H

6 0

4 years ago

Please help!! Is this an: Acid Base Neither

Liono4ka [1.6K]

Answer:

it is a weak acid

acid

Explanation:

formaldehyde is a weak acid (pK greater than 13),

3 0

2 years ago

Calculate hydrochloric acid (umol)in 200 ul of a 0.5173Msolution of acid?

strojnjashka [21]

Answer: The moles of hydrochloric acid is $1.0346\times 10^{-4}\mu mol$

Explanation:

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Or,

$\text{Molarity of the solution}=\frac{\text{Micro moles of solute}\times 10^6}{\text{Volume of solution (in }\mu L)}}$

We are given:

Molarity of solution = 0.5173 M

Volume of solution = $200\mu L$

Putting values in above equation, we get:

$0.5173M=\frac{\text{Micro moles of HCl}\times 10^6}{200\mu L}\\\\\text{Micro moles of HCl}=1.0346\times 10^{-4}\mu mol$

Hence, the moles of hydrochloric acid is $1.0346\times 10^{-4}\mu mol$

7 0

3 years ago

Do iron (III) chloride, potassium iodide, or potassium chloride catalyze the decomposition of hydrogen peroxide?

alexira [117]

Iron (III) chloride catalyzes the decomposition of hydrogen peroxide because the decomposition of hydrogen peroxide is usually inhibited by the presence of ions such as phosphate ions in solution. The iron ions that would result from the dissolution of iron (III) chloride have a charge of 3+ and would bond with the -3 charged phosphate ions, creating a non-charged FePO4 molecule and removing the decomposition inhibitor from the solution. Potassium iodide and potassium chloride both are more strongly bonded than a transition metal compound and would lack the necessary charged iron ion when added to hydrogen peroxide.

3 0

3 years ago

T or F: Lone pairs around the oxygen atom of a water molecule play no role in determining its molecular geometry?

Mama L [17]

Answer:

Explanation:

They play a very important part. The geometry is not a straight line. It is an angle over 90 which means that the molecule has the same general shape as a boomerang. The two hydrogens and the 2 lone electron pairs try to get away as far as possible from each other. The actual shape results in a tetrahedron shape. But the two hydrogens and 1 oxygen actually look like the aforementioned boomerang.

5 0

3 years ago