Answer:
% purity of limestone = 96.53%
Explanation:
Question (4).
Weight of impure CaCO₃ = 25.9 g
Molecular weight of CaCO₃ = 40 + 12 + 3(16)
= 100 g per mole
We know at S.T.P. number of moles of CO₂ = 1 and volume = 22.4 liters
From the given reaction, 1 mole of CaCO₃ reacts with 1 mole or 22.4 liters of
CO₂.
∵ 22.4 liters of CO₂ was produced from CaCO3 = 100 g
∴ 1 liter of CO₂ will be produced by CaCO₃ = 
∴ 5.6 liters of CO₂ will be produced by CaCO₃ = 
= 25 g
Therefore, % purity of CaCO₃ = 
= 
= 96.53 %
Answer:
- you have to do maths in all 3
- atoms make up everything even parts of a cel and theyre studied in chem and physics
- chemistry is used in biology by finding out what different substances are eg cytoplasm in a cell
Paleolithic Era
During the Paleolithic Era, early humans used mostly stone tools but at times also used wood or bone tools.
Answer:
CF4 is non polar
polar, no net, nonpolar
Explanation:
The overall polarity of a molecule depends on the presence of polar bonds within the molecule and the orientation of the polar bonds to produce an overall dipole moment. This implies that the presence of polar bonds in a molecule does not automatically imply that such molecule is polar or will display on overall dipole moment. The orientation of the individual dipoles affects the overall dipole moment of the molecule.
A polar molecule results from an unequal/unsymmetrical sharing of valence electrons. While there may be unequal sharing of electrons in the individual bonds, in a nonpolar molecule like CF4 these bonds are evenly distributed and cancel out. There is no net dipole and the CF4 is non-polar. Hence the order of words chosen in the answer to fill in the blanks.
It is a simple stoichiometry problem. We have been given with balanced equation and 5.00 moles of HCl and have to calculate the moles of H2.
<span>From the balanced equation it is being clear that 2 moles of HCl are produced by 1 mole of H2. so, 1 mole of HCl will be produced by 1/2 moles of H2. So, the mole ratio of H2 and HCl is 1:2 </span>
<span>to calculate the moles of H2 for the given moles of HCl, multiply the moles of HCl by the mole ratio of H2 and HCl. </span>
<span>5.00 mole HCl x (1 mole H2/ 2 mole HCl) </span>
<span>= 2.50 mole H2 </span>
<span>so, to produce 5.00 moles of HCl, 2.50 moles of H2 are required.</span>
