Answer:
1) Salts X and Y
2) The solubility of the salts
3) a) The solvent
b) The solvent temperature
Explanation:
1) The independent variable is the variable that is suspected to be the cause of the subject of the investigation
The given investigation is meant to investigate the solubility of different salts
Therefore, the solubility is expected to be dependent on the type of salt, and the independent variable is the type of salt, X or Y
2) The dependent variable is the effect meant to be observed in the investigation, which is the solubility of the salt in water at room temperature
3) The control variables are the variables which are held constant during the investigation, including;
a) The solvent used if the investigation; water
b) The temperature of the solvent; Room temperature
<u>Answer:</u>
Nitrogen gas be a mineral only, if it is in organic forms.
<u>Explanation:</u>
Most of the forms of organic nitrogen is not be taken by plants, with the exception in the form of small organic molecules. Also plants can promptly take the nitrogen when it is in other forms like ammonia and nitrate.
The microorganisms in the soil converts the organic forms of nitrogen to mineral form when they decompose organic matters and also fresh plant residues. This type of process is called mineralisation.
Answer:
10.85 g of water
Explanation:
First we write the balanced chemical equation

Then we calculate the number of moles of nitric acid produced
n(HNO3) = 
According to the balanced equation, water needed in moles is always half the number of moles of HNO3 produced. So since we will produce 1.2044 mol of HNO3, we will need 0.6022 mol of water. Now to calculate what mass that is:
mass(water)=number of moles*molar mass=0.6022mol*18.02g/mol=10.85g
The equation is balanced as follows
Mgcl2 +2AgNo3 -->2Agcl +Mg(No3)2
from equation above 1 mole of MgCl2 reacted with 2 moles of AgNo3 to form 2 moles of AgCl2 and 1 mole of Mg(NO3)2
when balancing equation the number of atom of element should be the same on each side of equation.