Explanation:
Z = atomic mass of the element and , A = atomic mass of the element .
a) Z = 11, A = 23
Element = Sodium
symbol: ²³₁₁Na .
b) Z = 28, A = 64
Element = Nickel
symbol: ⁶⁴₂₈Ni .
c) Z = 50, A = 115
Element = tin
symbol: ¹¹⁵₅₀Sn .
d) Z = 20, A = 42
Element = Calcium
symbol: ⁴²₂₀Ca .
<span>Density is a value for
mass, such as kg, divided by a value for volume, such as m3. Density is a
physical property of a substance that represents the mass of that substance per
unit volume. We calculate as follows:
PV = nRT
PV = mRT/ Molar mass
m/V = P(molar mass)/RT
Density = P(molar mass)/RT
Density = 2.0 ( 30.97 ) / 0.08206 ( 20 + 273.15) = 2.57 g/L <----First option</span>
Answer:
1.72 M
Explanation:
Molarity is the molar concentration of a solution. It can be calculated using the formula a follows:
Molarity = number of moles (n? ÷ volume (V)
According to the information provided in this question, the solution has 58.7 grams of MgCl2 in 359 ml of solution.
Using mole = mass/molar mass
Molar mass of MgCl2 = 24 + 35.5(2)
= 24 + 71
= 95g/mol
mole = 58.7g ÷ 95g/mol
mole = 0.618mol
Volume of solution = 359ml = 359/1000 = 0.359L
Molarity = 0.618mol ÷ 0.359L
Molarity = 1.72 M
