Answer: 
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here iron is having an oxidation state of +3 called as 
cation and oxide 
is an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral 
.
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Answer: Option (4) is the correct answer.
Explanation:
A mixture is defined as a substance that contains two or more different substance that are physically mixed with each other.
If solute particles are evenly distributed in a solvent then it is known as a homogeneous mixture.
For example, salt dissolved in water is a homogeneous mixture.
If solute particles are unevenly distributed into the solvent then it is known as a heterogeneous mixture.
For example, sand in water is a heterogeneous mixture.
Thus, we can conclude that the statement a mixture must contain at least two different substances, is correct about mixtures.
Answer:
6, double
Explanation:
Hex- is a prefix for number 6.
Ene- is a suffix for a double bond.
Answer:
1) correct
2) incorrect
3) correct
4)incorrect
Explanation:
1) A Lewis acid is a substance that accepts a nonbonding pair of electrons.
A Bronsted-Lowry acid is a substance that donates a proton H⁺
Since the donation of a proton involves the acceptance of a pair of electrons, every Bronsted-Lowry acid is also a Lewis acid.
2)A Lewis acid not necessarily needs to have a proton to be donated.
3) Conjugated acids of weak bases are strong acids and conjugated acids of strong bases are weak acids.
4)K⁺ comes from a strong base, therefore is does not have an acidic behaviour.
To solve this we assume
that the gas is an ideal gas. Then, we can use the ideal gas equation which is
expressed as PV = nRT. At a constant temperature and number of moles of the gas
the product of PV is equal to some constant. At another set of condition of
temperature, the constant is still the same. Calculations are as follows:
P1V1 =P2V2
P2 = P1 x V1 / V2
P2 = 2.0 x 1.5 / 3
<span>P2 = 1 atm</span>
