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
This is late but for anyone else who needs it...It's D. Far left
Nonmetal your welcome
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Answer:
0.26 moles
Explanation:
Number of moles = mass/molar mass
Mass of SiO2 = 15.5g
Molar mass of SiO2 = 60.08g/mol
Number of moles = 15.5g/60.08g/mol
=0.257
= 0.26 moles
