Correct Answer: A. Copper

Explanation

Most alkali metals and alkaline earth metals react with water to produce hydrogen. The alkali metals comprise Group 1 of the periodic table, and include lithium, sodium, potassium, etc.

- Zinc is not much reactive with cold or room temperature water but reacts with steam to form zinc oxide and liberate hydrogen gas.

- Copper lies below hydrogen in the activity series of metals, therefore it can not displace hydrogen from water

Correct Answer: D) 50cm³

Explanation

The question is about a reaction between hydrogen and oxygen gases, and the residual gas volume after the reaction mixture passes through an alkaline solution of pyrogallol.

First, let's consider the balanced chemical equation for the reaction between hydrogen and oxygen gases:

\(2H_2(g) + O_2(g) \rightarrow 2H_2O(g)\)

From the equation, we can see that 2 moles of hydrogen gas react with 1 mole of oxygen gas to form 2 moles of water vapor. Now let's examine the initial conditions: 50 cm\(^3\) of hydrogen and 100 cm\(^3\) of oxygen at 110\(^{\circ}\)C and 1 atm.

Since the volume ratio of hydrogen to oxygen is 1:2 in the balanced equation, the reaction will consume all 50 cm\(^3\) of hydrogen and half of the 100 cm\(^3\) of oxygen, leaving 50 cm\(^3\) of oxygen unreacted.

Now, let's consider the effect of passing the reaction mixture through an alkaline solution of pyrogallol. Pyrogallol has a strong affinity for oxygen and will absorb the unreacted oxygen gas. Therefore, the residual gas volume after passing through the pyrogallol solution will only consist of the water vapor produced by the reaction.

Since we started with 50 cm\(^3\) of hydrogen, and the balanced equation shows a 1:1 ratio of hydrogen to water vapor, the water vapor produced also has a volume of 50 cm\(^3\). Therefore, the volume of the residual gas is50 cm\(^3\), which corresponds toOption D.

Correct Answer: A)

1.88dm³

Explanation

This question is testing your knowledge on the relationship between temperature and volume of a gas, as well as the ideal gas law. The ideal gas law is a formula that describes the behavior of gases at different temperatures, pressures, and volumes.

The question provides us with the initial volume of the gas at 25

Correct Answer: A. Chromatography

Explanation

Chromatography is a separation technique used to separate and analyze components of a mixture based on their differential partitioning between a stationary phase (e.g., paper or a column) and a mobile phase (e.g., solvent). Different components move at different rates, leading to separation.

Correct Answer: B)

RCOO\(^-\) + H\(^+\)

Explanation

This Chemistry question is about alkanoic acids and how they ionize in solution. The question is asking what products are formed when alkanoic acids ionize in solution.

Alkanoic acids are weak acids, which means they only partially ionize in solution. When an alkanoic acid ionizes in solution, it forms a negatively charged ion called a carboxylate ion or RCOO\(^-\), and a positively charged hydrogen ion or H\(^+\). Out of the given options, option B is correct. Option B states that alkanoic acids ionize in solution to give RCOO\(^-\) + H\(^+\). This means that the alkanoic acid loses a hydrogen ion, which becomes H\(^+\), and the remaining part of the molecule becomes RCOO\(^-\). Option A is incorrect because it suggests that the alkanoic acid loses an electron to form R\(^+\) and COOH. This is not correct because the alkanoic acid does not lose an electron during ionization. Option C is incorrect because it suggests that the alkanoic acid gains a hydrogen ion to form RCOO\(^+\) and H\(^-\). This is not correct because the alkanoic acid loses a hydrogen ion during ionization. Option D is incorrect because it suggests that the alkanoic acid loses a hydroxide ion to form RCO\(^+\) and OH\(^-\). This is not correct because the alkanoic acid loses a hydrogen ion during ionization, not a hydroxide ion. In summary, when alkanoic acids ionize in solution, they form RCOO\(^-\) and H\(^+\). It is important to understand that alkanoic acids are weak acids and only partially ionize in solution.

Correct Answer: D) ethanol and ethanamide

Correct Answer: B. 109.5°

Correct Answer: D. 750 cm₃

Correct Answer: A. HF

Correct Answer: D) fehling's solution