<span>C7H8
First, determine the number of relative moles of each element we have and the molar masses of the products.
atomic mass of carbon = 12.0107
atomic mass of hydrogen = 1.00794
atomic mass of oxygen = 15.999
Molar mass of CO2 = 12.0107 + 2 * 15.999 = 44.0087
Molar mass of H2O = 2 * 1.00794 + 15.999 = 18.01488
We have 5.27 mg of CO2, so
5.27 / 44.0087 = 0.119749 milli moles of CO2
And we have 1.23 mg of H2O, so
1.23 / 18.01488 = 0.068277 milli moles of H2O
Since there's 1 carbon atom per CO2 molecule, we have
0.119749 milli moles of carbon.
Since there's 2 hydrogen atoms per H2O molecules, we have
2 * 0.068277 = 0.136554 milli moles of hydrogen atoms.
Now we need to find a simple integer ratio that's close to
0.119749 / 0.136554 = 0.876937
Looking at all fractions n/m where n ranges from 1 to 10 and m ranges from 1 to 10, I find a closest match at 7/8 = 0.875 with an error of only 0.001937, the next closest match has an error over 6 times larger. So let's go with the 7/8 ratio.
The numerator in the ratio was for carbon atoms, and the denominator was for hydrogen. So the empirical formula for toluene is C7H8.</span>
Answer:
0.497 moles/L
Explanation:
The reaction that takes place is:
- C₃H₆O₃ + NaOH → C₃H₅ONa + H₂O
First we c<u>alculate the moles of lactic acid in 0,821 g</u>, using its molar mass:
- 0,821 g ÷ 90 g/mol = 9,122x10⁻³mol lactic acid
<em>One mole of lactic acid reacts with one mole of sodium hydroxide</em> (it is a monoprotic acid), so in 18,34 mL of NaOH solution there are 9,122x10⁻³moles of NaOH:
- 18.34 mL ÷ 1000 = 0,01834 L
- 9,122x10⁻³mol ÷ 0,01834 L = 0.497 moles/L
Answer:
61.3 g/mol
Step-by-step explanation:
We can use the <em>Ideal Gas Law</em> to solve this problem:
pV = nRT
Since n = m/M, the equation becomes
pV = (m/M)RT Multiply each side by M
pVM = RT Divide each side by RT
M = (mRT)/(pV)
<em>Data:
</em>
m = 0.675 g
R = 0.0.083 14 bar·L·K⁻¹mol⁻¹
T = 0 °C = 273.15 K
p = 1 bar
V = 250 mL = 0.250 L
<em>Calculation:
</em>
M= (0.675 × 0.083 14 × 273.15)/(1 × 0.250)
M= 15.33/0.250
M= 61.3 g/mol
Answer:
The answer is
<h2>[OH-] = 1.66 × 10^-14 M</h2>
Explanation:
To find the [OH-] we must first find the pH and the pOH of the solution
That's
pH + pOH = 14
pOH = 14 - pH
To find the pH we use the formula
pH = -log [H3O+]
From the question
[H3O+] = 0.6 M
pH = - log 0.6
pH = 0.22
pOH = 14 - 0.22
pOH = 13.78
We can now find the [OH -] in the solution using the formula
pOH = - log [OH-]
13.78 = - log [OH-]
Find the antilog of both sides
We have the final answer as
<h3>[OH-] = 1.66 × 10^-14 M</h3>
Hope this helps you
Answer:
That's a major lab mistake! Never pour chemicals in sink unless otherwise stated by the lab instructor. They should go in a properly labelled waste jar or similar container. Apparatus should not be left in sink, it should be washed and cleaned, and returned to where it came from.
Explanation:
