Answer:
A) Sample B has more calcium carbonate molecules
Explanation:
M = Molar mass of calcium carbonate = 100.0869 g/mol
= Avogadro's number = 
For the 4.12 g sample
Moles of a substance is given by
Number of molecules is given by
For the 19.37 g sample
Number of molecules is given by
So, sample B has more calcium carbonate molecules.
The ratio of the elements of carbon, oxygen, calcium atoms, ions, has to be same in both the samples otherwise the samples cannot be considered as calcium carbonate. Same is applicable for impurities. If there are impurites then the sample cannot be considered as calcium carbonate.
These problems are a bit interesting. :)
First let's write the molecular formula for ammonium carbonate.
NH4CO3 (Note! The 4 and 3 are subscripts, and not coefficients)
17.6 gNH4CO3
Now to convert to mol of one of our substances we take the percent composition of that particular part of the molecule and multiply it by our starting mass. This is what it looks like using dimensional analyse.
17.6 gNH4CO3 * (Molar Mass of NH4 / Molar Mass of NH4CO3)
Grab a periodic table (or look one up) and find the molar masses for these molecules! Well. In this case I'll do it for you. (Note: I round the molar masses off to two decimal places)
NH4 = 14.01 + 4*1.01 = 18.05 g/mol
NH4CO3 = 14.01 + 4*1.01 + 12.01 + 3*16.00 = 78.06 g/mol
17.6 gNH4CO3 * (18.05 molNH4 / 78.06 molNH4CO3)
= 4.07 gNH4
Now just take the molar mass we found to convert that amount into moles!
4.07 gNH4 * (1 molNH4 / 18.05 gNH4) = 0.225 molNH4
Answer:
because they cannot keep their body temperature constant.
Answer:
Formed by adding 5 g of sugar to 1 L of water
Explanation:
The substance formed by adding 5 g of suagr to 1 L of water is a mixture.
<em>A mixture is defined as two or more substances that are physically mixed but do not react together. It thus means that the component substances of a mixture can be retrieved through appropriate means of separations.</em>
<u>A mixture of sugar and water can be separated by evaporation. The mixture is heated and the vapor from the boiling water can be condensed to retrieve the water while the residue will give the sugar that was initially dissolved in it. </u>
The products formed from other descriptions in the illustration cannot be separated ordinarily and thus, are not considered to be mixture. The components have been chemically combined together.
Answer:
a. decrease the amount of the common ion in the system
Explanation:
The correct option is - a. decrease the amount of the common ion in the system
Reason -
Adding a common ion decreases solubility, as the reaction shifts toward the left to relieve the stress of the excess product.
Adding a common ion to a dissociation reaction causes the equilibrium to shift left, toward the reactants, causing precipitation.
