Answer:
The correct answer is option c.
Explanation:
Formula used to determine an average atomic mass :

Mass of isotope Sb-121 = 120.904 amu
Fractional abundance of Sb-121 = 57.21% = 0.5721
Mass of isotope Sb-123 = 122.904 amu
Fractional abundance of Sb-123 = 42.79% = 0.4279
Average atomic mass of Sb:

Molecular weight of N2
gram Atomic weight of N is 14 g.
gram Molecular weight = 14 g×2
= 28 g
Liter concepts
1 liter of gas always occupies 1 gram molecular weight .
Application of the concept
5.75 liter gives 0.257g
1 mole will occupy 28 g
0.257 will occupy 28 g × 0.257
= 7.196 g
The mass of the gas is 7.196 g.
Hope it helps you
When MgO and H2O react they form Magnesium Hydroxide Mg(OH)2
Answer:
The correct answer is B. Dull appearance
Explanation:
The moles which were measured out is calculated using the following formula
moles = mass/molar mass
molar mass of CuBr2.4H20 = 63.5 Cu + ( 2 x79.9) br + ( 18 x4_) h20 = 295.3 g/mol
moles is therefore= 5.2 g/ 295.3 g/mol= 0.0176 moles