P waves are classified as

An unknown compound contains only carbon, hydrogen, nitrogen, and oxygen. Complete combustion of a 2.77 g sample of the compound

alisha [4.7K]

The molecular formula of the unknown compound is determined as C₉H₁₁NO₂.

<h3>Molecular formula of the compound</h3>

The molecular formula is calculated as follows;

CHNO + O₂ ------------> CO₂ + H₂O

Mass of carbon, C: = (6.64 x 12)/44 = 1.81 g in 2.77 g sample

Mass of hydrogen, H: = (1.67 x 2)/18 = 0.186 g in 2.77 g sample

Mass of Nitrogen, N: = (2.77 x 0.143)/1.69 = 0.234 g

Mass of oxygen, O: = 2.77 g - 1.81 g - 0.186 g - 0.234 g = 0.54 g

<h3>molar ratio of the elements: </h3>

C = 1.81 g = 0.15 mol

H = 0.186 g = 0.186 mol

N = 0.234 g = 0.017 mol

O = 0.54 g = 0.0337 mol

divide through with the smallest number of moles (0.017 mol);

C = 9

H = 11

N = 1

O = 2

Molecular formula = C₉H₁₁NO₂

Check the molar mass of the compound = (9 x 12) + (11 x 1) + (14) + (2 x 16) = 165 g/mol

Thus, the molecular formula of the unknown compound is determined as C₉H₁₁NO₂.

Learn more about molecular mass here: brainly.com/question/21334167

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4 0

2 years ago

A chemist dissolves 867. mg of pure barium hydroxide in enough water to make up 170. mL of solution. Calculate the pH of the sol

Ilya [14]

Answer: The pH of the solution is 11.2

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

$Molarity=\frac{n\times 1000}{V_s}$

where,

n = moles of solute

$V_s$ = volume of solution in ml

moles of $Ba(OH)_2$ = $\frac{\text {given mass}}{\text {Molar mass}}=\frac{0.867g}{171g/mol}=0.00507mol$ (1g=1000mg)

Now put all the given values in the formula of molality, we get

$Molarity=\frac{0.00507\times 1000}{170}$

$Molarity=0.0298$

pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration.

$pOH=-\log [OH^-]$

$Ba(OH)_2\rightarrow Ba^{2+}+2OH^{-}$

According to stoichiometry,

1 mole of $Ba(OH)_2$ gives 2 mole of $OH^-$

Thus 0.0298 moles of $Ba(OH)_2$ gives = $\frac{2}{1}\times 0.0298=0.0596$ moles of $OH^-$

Putting in the values:

$pOH=-\log[0.0596]=2.82$

$pH+pOH=14$

$pH=14-2.82$

$pH=11.2$

Thus the pH of the solution is 11.2

8 0

3 years ago

HELP PLEASE I GIVE 21 POINTS!!!! +BRAINLIEST!!!!!!!

cricket20 [7]

You could write about a fear you may have had as a child, eg. the dark, or underneath the bed, etc...

7 0

3 years ago

Read 2 more answers

Why are leaves different colors?

Marina86 [1]

<span>Why are leaves different colors?</span><span>
The chlorophyll breaks down</span>

6 0

3 years ago

0.250 moles of NaCl is dissolved in 0.850 L of solution. What is the molar concentration?

Nuetrik [128]

Considering the definition of molarity, the molar concentration is 0.294 $\frac{moles}{liter}$ .

Molarity reflects the concentration of a solution indicating the number of moles of solute that are dissolved in a given volume.

The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:

$molarity=\frac{amount of moles of solute}{volume}$

Molarity is expressed in units $\frac{moles}{liter}$ .

In this case, you know:

amount of moles of solute= 0.250 moles
volume= 0.850 L

Replacing in the definition of molarity:

$molarity=\frac{0.250 moles}{0.850 L}$

Solving:

molarity= 0.294 $\frac{moles}{liter}$

Finally, the molar concentration is 0.294 $\frac{moles}{liter}$ .

Learn more about molarity with this example: brainly.com/question/15406534?referrer=searchResults

6 0

3 years ago