The answer to this question will be C
Answer:
1.23 M
Explanation:
Molarity of a substance , is the number of moles present in a liter of solution .
M = n / V
M = molarity
V = volume of solution in liter ,
n = moles of solute ,
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
From the question ,
w = given mass of NaCl = 7.2 g
As we know , the molecular mass of NaCl = 58.5 g/mol
Moles is calculated as -
n = w / m = 7.2 g / 58.5 g/mol = 0.123 mol
Molarity is calculated as -
V = 100ml = 0.1 L (since , 1 ml = 1/1000L )
M = n / V = 0.123 mol / 0.1 L = 1.23 M
the answer is A. SnCl2 . 2H2O
Answer:
Quartz.
Explanation:
According to the characteristics given in the question the mineral must surely be Quartz.
Quartz does not react with hydrochloric acid.
Its is pink in color and has anon metallic luster. It has a specific gravity of 2.65. Quartz is continuous framework of SiO4 , with each oxygen being shared with two tetrahedra, giving an overall chemical formula of SiO2.
