Explanation

 In any mixture of gases, the sum of the mole fractions of all components is always equal to 1.

Explanation

 Fe atomic number = 26 → Fe: [Ar] 3d⁶ 4s²  

Fe²⁺ loses 2 electrons → becomes 3d⁶ → 4 unpaired electrons.  

Others have fewer or no unpaired electrons.

Explanation

 Lattice energy increases with:  

- Higher charge of ions  

- Smaller size of ions  

Among the given, Na⁺ is common. F⁻ is the smallest anion, so NaF has the strongest electrostatic attraction → highest lattice energy.

Explanation

Na₂CO₃ is the salt that will produce the highest pH when dissolved in water because it is derived from a strong base (NaOH) and a weak acid (H₂CO₃).

Explanation

The pressure of oxygen inside a bomb calorimeter is typically 20-40 atmospheres or 20-40 bar,

It is equivalent to 2026.5 to 4053 kPa or 2.0265 to 4.053 MPa.

This high pressure ensures complete combustion of the sample being tested. 

Explanation

 The decomposition of dinitrogen pentoxide (N2O5) as shown in the reaction 2N2O5 → 2N2O4 + O2 is a first-order reaction.

This means the rate of the reaction is directly proportional to the concentration of N2O5. 

Explanation

Calcium (Ca) typically has an oxidation number of +2.

Oxygen (O) typically has an oxidation number of -2.

In the chlorite ion (ClO2-), let the oxidation number of Cl be 'x'.

The total charge of the chlorite ion is -1.

So, the equation becomes: x + 2*(-2) = -1

Solving for x: x - 4 = -1, therefore x = +3

Since there are two chlorite ions in the compound, the overall oxidation number of Cl in Ca(ClO2)2 is +3.

Explanation

The relative lowering of vapor pressure is given by the formula: 

Relative lowering of vapor pressure = (Mole fraction of solute)/(Mole fraction of solvent + Mole fraction of solute)

Calculating the mole fractions:

Moles of glucose = (18 g / 180 g/mol) = 0.1 mol 

Moles of water = (90 g / 18 g/mol) = 5 mol

Mole fraction of glucose = 0.1 / (0.1 + 5) = 0.02 

Mole fraction of water = 1 - 0.02 = 0.98 

Substituting into the formula:

Relative lowering of vapor pressure = 0.02 / (0.02 + 0.98) = 0.02 / 1 = 0.02 

Therefore, the relative lowering of vapor pressure is 0.02, which is equivalent to 1/50. 

Explanation

Ionic character is determined by the difference in electronegativity between the atoms in a bond.

A larger electronegativity difference indicates a greater degree of ionic character.

CsF has the largest electronegativity difference due to the extremely high electronegativity of fluorine and the very low electronegativity of cesium. 

Explanation

An ammeter is always connected in series with a circuit to measure the current. 

In a series circuit, the current flows through each component one after the other, meaning the same current passes through every device in the circuit.

Since an ammeter is designed to measure the current flowing through a circuit, placing it in series ensures that the entire current passes through it.