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
Answer:
Elements in same column of periodic table have same properties.
Explanation:
The elements in the same group have same number of valance electrons thus have similar properties.
Consider the elements of group two i.e alkaline earth metals. All have two valance electrons and show similar properties.
Magnesium, barium, calcium etc.
All alkaline earth metals form salt with halogens.e.g,
Mg + Cl₂ → MgCl₂
Ba + Br₂ → BaBr₂
Mg + Br₂ → MgBr₂
Ca + Br₂ → CaBr₂
They react with oxygen and form oxides of respective metal.
2Mg + O₂ → 2MgO
2Ba + O₂ → 2BaO
2Ca + O₂ → 2CaO
these oxides form hydroxide when react with water,
MgO + H₂O → Mg(OH)₂
BaO + H₂O → Ba(OH)₂
CaO + H₂O → Ca(OH)₂
With nitrogen it produced nitride,
3Mg + N₂ → Mg₃N₂
3Ba + N₂ → Ba₃N₂
3Ca + N₂ → Ca₃N₂
With acid like HCl,
Mg + 2HCl → MgCl₂ + H₂
Ba + 2HCl → BaCl₂ + H₂
Ca + 2HCl → CaCl₂ + H₂
The temperature of the gas, the hotter they get the faster they move. the colder they get, the slower they move
Answer:
reduced
Explanation:
To win the metallic product from the oxide, it demands that the metal be reduced.
During reduction a metal will:
- gain electrons.
- there would be removal of oxygen from the specie
- there would be decrease in oxidation number of the atom
- decrease in the number of electronegative atom surrounding the element.
The specie that is reduced will become the oxidant and reducing agent in the chemical reaction.