Answer:
Molecular formula = C20H30
Explanation:
NB 440mg = 0.44g, 135mg= 0.135g
From the question, moles of CO2= 0.44/44= 0.01mol
Since 1 mol of CO2 contains 1mol of C, it implies mol of C = 0.01
Also from the question, moles of H2O = 0.135/18= 0.0075mole
Since 1 mol of H2O contains 2mol of H, it implies mol of H = 0.0075×2= 0.015 mol of H
To get the empirical formula, divide by smallest number of mole
Mol of C = 0.01/0.01=1
Mol of H = 0.015/0.01= 1.5
Multiply both by 2 to obtain a whole number
Mol of C =1×2 = 2
Mol of H= 1.5×2 = 3
Empirical formula= C2H3
[C2H3] not = 270
[ (2×12) + 3]n = 270
27n = 270
n=10
Molecular formula= [C2H3]10= C20H30
Answer:
78 moles of the solute
Explanation:
From the question;
- Molarity of the solution is 6.50 M
- Volume of the solution is 12.0 L
We want to determine the number of moles needed
We need to know that;
Molarity = Number of moles ÷ Volume
Therefore;
Number of moles = Molarity × Volume
Hence;
Number of moles = 6.50 M × 12.0 L
= 78 moles
Thus, the moles of the solute needed is 78 moles
<span>Selenium (se)
........
.....</span>
This is a physical phase change it is still water it just separated and became less and less.it stays water though
You must burn 1.17 g C to obtain 2.21 L CO₂ at STP.
The balanced chemical equation is
C + O₂ → CO₂.
<em>Step 1</em>. Convert <em>litres of CO₂ to moles of CO₂</em>.
STP is <em>0 °C and 1 bar</em>. At STP the volume of 1 mol of an ideal gas is 22.71 L.
Moles of CO₂ = 2.21 L CO₂ × (1 mol CO₂/22.71 L CO₂) = 0.097 31 mol CO₂
<em>Step 2</em>. Use the molar ratio of C:CO₂ to <em>convert moles of CO₂ to moles of C
</em>
Moles of C = 0.097 31mol CO₂ × (1 mol C/1 mol CO₂) = 0.097 31mol C
<em>Step 3</em>. Use the molar mass of C to <em>calculate the mass of C
</em>
Mass of C = 0.097 31mol C × (12.01 g C/1 mol C) = 1.17 g C
It looks as if you are using the <em>old (pre-1982) definition</em> of STP. That definition gives a value of 1.18 g C.