Correct Answer: B. Fermentation

Correct Answer: B. 14.8%

Explanation

. % of C in Ca(HCO3)2 Molar mass of Ca(HCO3)2 = 40+(1+12+(16*3))2 =40+(13+48)2 =40+122 =162 C/Ca(HCO3)2 x 100 =12 * 2/162 * 100 =14.8%

Correct Answer: D) Q will form an electrovalent bond with S

Explanation

This question is about the electron configuration of four different elements, namely P, Q, R, and S. The question provides the number of electrons for each element, which are 6, 11, 15, and 17 respectively.

Based on this information, the question is asking which of the options best describes the type of bond that would be formed between two of the elements.

Option A suggests that P will form an electrovalent bond with R. An electrovalent bond is also known as an ionic bond, which involves the transfer of electrons from one atom to another. However, the electron configuration of P and R does not suggest that this type of bond would be formed.

Option B suggests that Q will form a covalent bond with S. A covalent bond involves the sharing of electrons between two atoms. This option is a possibility given the electron configuration of Q and S, but it is not the correct answer.

Option C suggests that R will form an electrovalent bond with S. Again, this is an ionic bond, which involves the transfer of electrons from one atom to another. This option is a possibility given the electron configuration of R and S, but it is not the correct answer.

Option D suggests that Q will form an electrovalent bond with S. This is the correct answer because the electron configuration of Q and S suggests that an ionic bond would be formed between the two elements. Q has 11 electrons, which means it has one electron short of a stable configuration, while S has 17 electrons, which means it has one electron more than a stable configuration. Q can transfer an electron to S to form a stable ionic compound.

In summary, the correct answer to this Chemistry question is Option D, which suggests that Q will form an electrovalent bond with S.

Correct Answer: C. 0.104 mol dm^-3

Correct Answer: D) isomeric

Explanation

Isomers are compounds whose molecular formulas are the same but chemical structures are different. The larger the molecule and more branched it is, the greater the number of isomers you can produce.

Explanation

(a)(i) Define the term Hygroscopic: Hygroscopic substance – is defined as a substance which absorbs moisture on exposure to the atmosphere but does not form solution or change state.

(ii) Give two differences between a physical and a chemical change:

(iii) Using the kinetic theory of gases, explain briefly the Charles' law: At constant pressure, when the temperature of a gas is increased, the molecules gain more kinetic energy and move faster. The distance between the molecule increases resulting in increased in the volume of the gas.

(b)(i) Arrange the following compounds in order of increasing boiling points:

CO\(_2\), CS\(_2\), NaH

CO\(_2\) — Weak vander Waal's forces.

CS\(_2\) — Stronger vander Waals's forces.

NaH — With ionic forces stronger than vander Waal's forces.

(ii) Write a balanced equation to illustrate the reaction of chlorine gas with cold dilute sodium hydroxide.

Cl\(_{2(g)}\) + 2NaOH\(_{(aq)}\) \(\to\) NaCl\(_{(aq)}\) ; NaCI\(_{(g)}\) + H\(_2\)O\(_{(l)}\)

(c) In a certain reaction, 15.0g of impure magnesium sample reacted with excess hydrochloric acid liberating 8.6dm\(^3\) of hydrogen gas at s.t.p

(I) Write a balance equation for the reaction.

Mg\(_{(g)}\) 2HCI\(_{(aq)}\) ---> MgCl\(_{2(ag)}\) + H\(_{2(g)}\).

(ii) Calculate the: I. Mass of pure magnesium in the sample

Mg + 2HCI \(\to\) MgCl\(_2\) + H\(_2\)

1 mole H\(_2\) = 1 moles mg

n(H\(_2\)) = \(\frac{8.6}{ 22.4}\)

= 0.384moles.

Hence, number of moles of Mg = 0.384moles

Mass of Mg = mole x molar mass

= 0.384 x 24

= 9.21g.

II. % purity = \(\frac{\text{Mass of pure Mg}}{\text{Mass of impure Mg}}\) x 100

Mg = \(\frac{9.21}{15.0}\) x 100

= 61.4%

Ill. From the equation;

Moles of cl\(^{-2}\) = 2 x moles of Mg

= 2 x 0.384

= 0.768 moles

No of Cl\(^{-}\) produced x N\(_A\)

= 0.768 x 6.02 x 10\(^{23}\)

= 4.62 x 10\(^{23}\) Cl\(^{-}\)

Correct Answer: D. will produce effervescence with magnesium ribbon

Correct Answer: B. neutral

Correct Answer: D. l, lll and IV only

Correct Answer: D. collision theory