Suggest why it might be difficult and dangerous to test sodium for electrical conductivity?
1 answer:
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Answer :
Oxidation number or oxidation state : It represent the number of electrons lost or gained by the atoms of an element in a compound.
Oxidation numbers are generally written with the sign (+) and (-) first and then the magnitude.
Rules for Oxidation Numbers are :
- The oxidation number of a free element is always zero.
- The oxidation number of a monatomic ion equals the charge of the ion.
- The oxidation number of Hydrogen (H) is +1, but it is -1 in when combined with less electronegative elements.
- The oxidation number of oxygen (O) in compounds is usually -2.
- The oxidation number of a Group 17 element in a binary compound is -1.
- The sum of the oxidation numbers of all of the atoms in a neutral compound is zero.
- The sum of the oxidation numbers in a polyatomic ion is equal to the charge of the ion.
Now we have to determine the oxidation state of the elements in the compound.
(a)
Let the oxidation state of 'S' be, 'x'
Hence, the oxidation state of 'S' is, (+6)
(b)
Let the oxidation state of 'Ca' be, 'x'
Hence, the oxidation state of 'Ca' is, (+2)
(c)
Let the oxidation state of 'Br' be, 'x'
Hence, the oxidation state of 'Br' is, (+1)
(d)
Let the oxidation state of 'N' be, 'x'
Hence, the oxidation state of 'N' is, (+5)
(e)
Let the oxidation state of 'Ti' be, 'x'
Hence, the oxidation state of 'Ti' is, (+4)
(f)
Let the oxidation state of 'Na' be, 'x'
Hence, the oxidation state of 'Na' is, (+1)
Answer:
Melting snow more efficiently in winters, understanding the components of mineral water
Explanation:
Let's split this question into two parts. First of all, ionic bonds:
- an example would be the application of the freezing point depression law. Remember that adding a solute to a specific solvent would decrease the freezing point of a solvent. This is the reason why we add ionic salts, NaCl, to snow in order to make it melt. Knowledge of the fact that 1 mol of NaCl, an ionic compound, dissociates into 2 mol of ions, sodium and chloride, yields us a van 't Hoff factor of 2 rather than 1 for non-electrolytes, molecular compounds. This means the same molality of ionic compounds would produce a twice larger decrease in the freezing point of a solvent;
- an example for ionic naming is more trivial. Remember the difference between, say, calcium and calcium cation. Sometimes we may read that mineral water is full of calcium. Having chemical knowledge of ionic compound naming would lead us to a conclusion that this is wrong! Mineral water doesn't have any calcium in it, we don't see any metal in mineral water. However, mineral water contains calcium cations,
and not
.