Q: According to recent views, which is the current representation of hydrated proton in aqueous solution?

The hydrated proton is represented as \$H_3O^+\$. Hence, the correct option is \$D\$.

Q: Among the hydrides given below which are reasonably good acid?

The \$pK_a\$ values of the given compounds are:\$HN_3\$: 4.6\$HF\$: 3.17\$NH_3\$: 38\$NaH\$: 35Higher the \$pK_a\$ lower will be the acidic strength. Since the \$pK_a\$ of \$NH_3\$ and \$NaH\$ are too high, they are basic in nature. Therefore, among the given compounds \$HF\$ and \$HN_3\$ are acidic and \$HF\$ is more acidic.Option B is correct.

Q: The hydride ion, \$H^{-}\$ is a stronger base than its hydroxide ion \$OH^{-}\$. Which of the following reactions will occur, if sodium hydride \$(NaH)\$ is dissolved in water?

Sodium hydride \$(NaH)\$ react with water to form hydrogen gas and the sodium hydroxide \$(NaOH)\$.\$NaH+H_2O\rightarrow H_2+NaOH\$i.e., \$Na^+, H^-\$ and \$H^+, OH^- \$ give rise to \$H_2\$ and \$NaOH\$. So, it is similar to option B.

Q: In which of the following reaction, dihydrogen acts as an oxidising agent?

As the calcium is having \$2\$ electrons more \$(1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2)\$ than the inert gas configuration, so it can give its two electrons to two hydrogens leading to the formation of \$CaH_2\$ and cause oxidation in \$Ca\$.\$Ca+H_2\rightarrow CaH_2\$Here, hydrogen is acting as the oxidising agent.

Q: The fuel used to produce electrical energy in the space rocket Saturn V, used by Neil Armstrong to reach the moon was:

The fuel used was a liquid mixture of \$H_{2}\$ and \$O_{2}\$.It was used for the following reasons:1. \$H_{2}\$ is a highly efficient fuel, as it has the highest calorific value.2. Mixing \$O_{2}\$ was required to support the combustion reaction: \$2H_{2}+O_{2}\rightarrow 2H_{2}O\$.3. Further, the water produced at the end of the combustion reaction provided a good source of pure drinking water for the astronauts.

Q: Hydrogen does not resemble alkali metals in which one of the following properties?

Hydrogen loses one electron and forms cation \$(H^+)\$.Oxides of hydrogen are neutral but metal oxides are basic in nature.Hydrogen combines with halogens \$(X)\$ and forms \$HX\$ molecule.Hydrogen loses one electron and causes reduction. Hence, it acts as a reducing agent.

Question 1

According to recent views, which is the current representation of hydrated proton in aqueous solution?

Accepted Answer

The hydrated proton is represented as $H_3O^+$. Hence, the correct option is $D$.

Question 2

Among the hydrides given below which are reasonably good acid?

Accepted Answer

The $pK_a$ values of the given compounds are:$HN_3$: 4.6$HF$: 3.17$NH_3$: 38$NaH$: 35Higher the $pK_a$ lower will be the acidic strength. Since the $pK_a$ of $NH_3$ and $NaH$ are too high, they are basic in nature. Therefore, among the given compounds $HF$ and $HN_3$ are acidic and $HF$ is more acidic.Option B is correct.

Question 3

The hydride ion, $H^{-}$ is a stronger base than its hydroxide ion $OH^{-}$. Which of the following reactions will occur, if sodium hydride $(NaH)$ is dissolved in water?

Accepted Answer

Sodium  hydride $(NaH)$ react with water to form hydrogen gas and the sodium hydroxide $(NaOH)$.$NaH+H_2O\rightarrow H_2+NaOH$i.e., $Na^+, H^-$ and $H^+, OH^- $ give rise to $H_2$ and $NaOH$. So, it is similar to option B.

Question 4

In which of the following reaction, dihydrogen acts as an oxidising agent?

Accepted Answer

As the calcium is having $2$ electrons more $(1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2)$ than the inert gas configuration, so it can give its two electrons to two hydrogens leading to the formation of $CaH_2$ and cause oxidation in $Ca$.$Ca+H_2\rightarrow CaH_2$Here, hydrogen is acting as the oxidising agent.

Question 5

The fuel used to produce electrical energy in the space rocket Saturn V, used by Neil Armstrong to reach the moon was:

Accepted Answer

The fuel used was a liquid mixture of $H_{2}$ and $O_{2}$.It was used for the following reasons:1. $H_{2}$ is a highly efficient fuel, as it has the highest calorific value.2. Mixing $O_{2}$ was required to support the combustion reaction: $2H_{2}+O_{2}\rightarrow 2H_{2}O$.3. Further, the water produced at the end of the combustion reaction provided a good source of pure drinking water for the astronauts.

Question 6

$2$ g of $Al$ is treated separately with an excess of dil. $H_{2}SO_{4}$ and excess of $NaOH$. The ratio of the volume of hydrogen evolved is :

Accepted Answer

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Question 7

Metal hydride on treatment with water gives________.

Accepted Answer

Metal hydrides react with water to form hydrogen gas and the metal hydroxide.Example: $LiH+H_2O\rightarrow H_2+LiOH$.

Question 8

Hydrogen finds a place in VII A group of periodic table because_________.

Accepted Answer

Hydrogen finds a place in VII A group of periodic table because hydrogen forms a compound $NaH$ like halogens $NaX$ ($X$ is halogen).

Question 9

The lightest element in the periodic table is_________.

Accepted Answer

The lightest element in the periodic table is hydrogen.Its atomic weight is $1.008$ amu.

Question 10

Hydrogen does not resemble alkali metals in which one of the following properties?

Accepted Answer

Hydrogen loses one electron and forms cation $(H^+)$.Oxides of hydrogen are neutral but metal oxides are basic in nature.Hydrogen combines with halogens $(X)$ and forms $HX$ molecule.Hydrogen loses one electron and causes reduction. Hence, it acts as a reducing agent.

Hydrogen

Chemistry
4247 Views

According to recent views, which is the current representation of hydrated proton in aqueous solution?

Among the hydrides given below which are reasonably good acid?

The hydride ion, $H^{-}$ is a stronger base than its hydroxide ion $O H^{-}$ . Which of the following reactions will occur, if sodium hydride $(N a H)$ is dissolved in water?

In which of the following reaction, dihydrogen acts as an oxidising agent?

The fuel used to produce electrical energy in the space rocket Saturn V, used by Neil Armstrong to reach the moon was:

$2$ g of $A l$ is treated separately with an excess of dil. $H_{2} S O_{4}$ and excess of $N a O H$ . The ratio of the volume of hydrogen evolved is :

Metal hydride on treatment with water gives________.

Hydrogen finds a place in VII A group of periodic table because_________.

The lightest element in the periodic table is_________.

Hydrogen does not resemble alkali metals in which one of the following properties?

Hydrogen

Chemistry 4247 Views

According to recent views, which is the current representation of hydrated proton in aqueous solution?

Among the hydrides given below which are reasonably good acid?

The hydride ion, H− is a stronger base than its hydroxide ion OH−. Which of the following reactions will occur, if sodium hydride (NaH) is dissolved in water?

In which of the following reaction, dihydrogen acts as an oxidising agent?

The fuel used to produce electrical energy in the space rocket Saturn V, used by Neil Armstrong to reach the moon was:

2 g of Al is treated separately with an excess of dil. H2​SO4​ and excess of NaOH. The ratio of the volume of hydrogen evolved is :

Metal hydride on treatment with water gives________.

Hydrogen finds a place in VII A group of periodic table because_________.

The lightest element in the periodic table is_________.

Hydrogen does not resemble alkali metals in which one of the following properties?

Chemistry
4247 Views

The hydride ion, $H^{-}$ is a stronger base than its hydroxide ion $O H^{-}$ . Which of the following reactions will occur, if sodium hydride $(N a H)$ is dissolved in water?

$2$ g of $A l$ is treated separately with an excess of dil. $H_{2} S O_{4}$ and excess of $N a O H$ . The ratio of the volume of hydrogen evolved is :