<span>The Mass Of The Products Of A Chemical Reaction Is equal to The Mass Of The Reactants.</span>
Answer: The correct answer is option a.
Explanation: Binary ionic compounds are the compounds made up of two ions, one is cation which is metal and another is anion which is a non-metal.
Rules for the naming of Binary Ionic compound.
1. First write the full name of cation.
2. The anion is named after using the suffix '-ide'. For example: If the anion is bromine, the name will be bromide and so on.
3. If the metal atom is Transition element, then the roman numeral is included after the metal name to indicate the oxidation number of the metal.
So, in order to write the name of Binary Ionic Compound, we first write metal followed by non-metal. Hence, the correct option is option a.
Aqueous nitric acid and aqueous ammonia reacts to form ammonium nitrate
HNO₃(aq)+NH₃(aq) = NH₄NO₃(aq)
HNO₃ +NH3 = NH₄ (+) + NO₃ (-)
Therefore the net ionic equation will be;
H⁺(aq) + NH₃ = NH₄⁺ (aq)
Answer : The crown is not made of pure (100%) gold.
Explanation :
Formula used :

where,
= apparent weight of the crown in water = 4.50 N
= actual weight = 5.00 N
= density of water = 
= density of crown = ?
Now put all the given values in the above formula, we get:


Density of crown < Density of gold

Thus, the crown is not made of pure (100%) gold.