Tag: chemistry

Quizzes (490) Questions (9892)

Questions Related to chemistry

Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen

Two oxides of a metal contain 72.4% and 70% of metal respectively? If formula of 2nd oxide is $ M _{2}O _{3} $, find that of the first ?

  1. MO
  2. $ M _{3}O _{4} $
  3. $ M _{3}O _{2} $
  4. $ MO _{2} $
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For the second oxide M2O3, 70% is metal, so 30% is oxygen. The ratio of moles M:O is (70/M) : (30/16) = 2:3. Solving gives M = 56 (Iron). For the first oxide (72.4% metal), ratio is (72.4/56) : (27.6/16) = 1.29 : 1.725 = 3:4. Thus, M3O4.

Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen

Which of the following is the most acidic?

  1. ${ P } _{ 2 }{ O } _{ 5}$
  2. ${ N } _{ 2 }{ O } _{ 5 }$
  3. ${ Sb } _{ 2 }{ O } _{ 5 }$
  4. ${ As } _{ 2 }{ O } _{ 5 }$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

As the electronegativity value of the element increases. the acidic character of the oxide also increases.

Here among $N,P,SI$ and $As$ the most electronegative is $N$.

Thus the most acidic is $N _2O _5$.

Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen

The most acidic oxide among the following is:

  1. $Cl _2O _5$
  2. $Cl _2O$
  3. $Cl _2O _3$
  4. $Cl _2O _7$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$Cl _2O _7$ is most acidic because on reacting with water , it gives  most strongest acid than the other three i.e., $HClO _4$ .

So, $Cl _2O _4$ is most acidic 

Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen

Which of the following statements are not correct ?

  1. All C - O bonds in $CO _3^{2-}$ are equal but not in $H _2CO _3$
  2. All C - O bonds in $HCO _2^-$ are equal but not in $HCO _2H$.
  3. C - O bond length in $HCO _2^-$ is longer than C - O bond length in $CO _3^{2-}$
  4. C - O bond length in $HCO _2^-$ and C - O bond length in $CO _3^{2-}$ are equal
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In HCO2- (formate ion), the C-O bond length is an average due to resonance, but it is generally shorter than a single bond and longer than a double bond. Comparing it to CO3(2-), the bond lengths are similar due to resonance, making statement C incorrect.

Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen

The type of ions responsible for scum formation are:

  1. oxides

  2. hydroxides

  3. chlorides

  4. carbonates
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The scum is formed when soap is used in hard water and hard water consists of carbonate. For this process $Oxides$ ions responsible for scum formation.

Hence,
The option $(A)$ is correct.

Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen

Which of the following oxide is least basic?

  1. $CrO$
  2. $Cr _2O _3$
  3. $CrO _3$
  4. $Cr _2O _4$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

As the oxidation state of a metal increases, its metallic character decreases and the covalent character of its oxide increases, leading to more acidic behavior. In CrO3, chromium is in the +6 oxidation state, making it acidic rather than basic, and thus it is the least basic among the choices.

Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen

An oxide of element $A$ was analysed and found to have mass ratio of $A$ to oxygen equal to $7:3$. Then formula of oxidation can be :

  1. $A _{3}O _{2}$
  2. $A _{2}O _{3}$
  3. $AO$
  4. $A _{2}O$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Mass ratio A:O = 7:3. Moles ratio = (7/AtomicWeightA) : (3/16). If A=56 (Iron), ratio = (7/56) : (3/16) = 0.125 : 0.1875 = 2:3. Formula is A2O3.

Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen

Titanium oxide $(TiO _{2})$ is heated in stream of hydrogen gas to give water and a new oxide $Ti _{x}O _{y}$. If $1.6\ gm$ of  $TiO _{2}$ produces $1.44\ gm$ of $Ti _{x}O _{y}$, the formula of new oxide is
[Atomic weight of $Ti=48$]:

  1. $TiO$
  2. $Ti _{2}O _{3}$
  3. $Ti _{2}O _{5}$
  4. $None\ of\ these$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Using mass conservation, moles of Ti in 1.6 g of TiO2 can be calculated. By finding the mass of oxygen removed during reduction by hydrogen, we determine the empirical formula of the resulting titanium oxide to be Ti2O3.

Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen

The pair of amphoteric oxides is: 

  1. $VO,\,C{r _2}{O _3}$
  2. ${V _2}{O _5},\,C{r _2}{O _3}$
  3. $V{O _2},\,C{r _2}{O _3}$
  4. ${V _2}{O _5},\,Cr{O _3}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
An amphoteric compound is a molecule or ion that can react both as an acid and as a base. Many metals (such as copper, zinc, tin, lead, aluminium, and beryllium) form amphoteric oxides or hydroxides. 

Amphoterism depends on the oxidation states of the oxide. Al2O3 is an example of an amphoteric oxide.

 V2O5 and Cr2O3 are amphoteric oxides because both react with alkalies as well as acids.

So, option B is correct
Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen

Which of the following oxide is most acidic? 

  1. $Na _2O$
  2. $MgO$
  3. $SiO _2$
  4. $Cl _2O _7$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$Na _2O$ , MgO are basic oxides.

$Cl _2O _7$  has highest acidity because it is an oxide of non metal .
Non metallic oxides are acidic 
This oxide reacts with water to give $HClO _4$ i,e,. strong acid.
So,