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.
1. B
The positive charge in water is provided by hydrogen, and gold provides the same charge. However, gold is not more reactive than hydrogen so it can not replace it in the compound.
2. In order to balance the equation, you must sure there are equal moles of each element on the left and right side of the equation:
2C₂H₆ + 7O₂ → 4CO₂ + ₆H₂O
3. The number of moles of sodium atoms on the left of the equation must be equal to the number of moles of sodium atoms on the right, as per the law of conservation of mass. The answer is B.
4. C.
A synthesis reaction usually results from single displacement because some element or compound is produced in its pure form
5. B.
The gas being produced is being synthesized.
Answer:
a. 0.5 mol
b. 1.5 mol
c. 0.67
Explanation:
Fe3+ + SCN- -----> [FeSCN]2+
a. The ratio of the product to Fe3+ is 1:1. Meaning that if 0.5 mol of product was produced up then 0.5 mol of Fe3+ was used. Leaving 0.5 mol remaining at equilibrium
b. The ratio of the product to SCN= is 1:1. Meaning that if 0.5 mol of product was produced up then 0.5 mol of SCN- was used. Leaving 1.5 mol remaining at equilibrium
c. KC = 0.5/(0.5*1.5) = 0.67
Answer:
BaO
Explanation:
The barium oxide chemical formula is BaO. The molar mass is 153.33 g/mol. The molecule is formed by one barium cation Ba2+ and one oxide anion O2-. Both ions are bound by one ionic bond.
Mixing water and sugar is a physical change. A physical change is just a change in the form of the substance, whereas a chemical change is when the substance itself changes… chemically. An easy way to figure out which is which is trying to "undo" the change. If it can be undone, it is physical.
