Tag: chemistry

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Multiple choice chemistry nitrogen and sulfur nitrogen gas component of air - nitrogen nitrogen

The mixture of $CO$ and $N _2$ is called as :

  1. Water gas

  2. Producer gas

  3. Synthetic gas

  4. Marsh gas
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water gas is a synthesis gas, containing carbon monoxide and hydrogen. It is a useful product but requires careful handling due to its flammability and the risk of carbon monoxide poisoning. 
Producer gas: a gas composed of carbon monoxide, hydrogen, and nitrogen, obtained by passing air and steam through incandescent coke.
Syngas/synthesis gas, is a fuel gas mixture consisting primarily of hydrogen, carbon monoxide, and very often some carbon dioxide.
Marsh gas is methane $CH _4$.

Multiple choice chemistry nitrogen and sulfur nitrogen gas component of air - nitrogen nitrogen

Nitrogen molecule is chemically less active because of its :

  1. small atomic energy.

  2. high dissociation energy.

  3. high electronegativity.

  4. stable electronic configuration.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Nitrogen molecule is chemically less active because of its high dissociation energy. Nitrogen molecule contains triple bond between two atoms which is very strong and requires high energy for splitting the two nitrogen atoms of a molecule. 


Multiple choice chemistry periodic table mendeleef's periodic table mendeleev's periodic law and its limitations mendeleev's periodic table development of the modern periodic table into the history

In Mendeleev's periodic table few elements that are chemically similar are placed in the same groups.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Mendeleev arranged the elements having similar configuration placed in the vertical columns as they will have the same unpaired electrons hence reflecting the similar properties. In Mendeleev's periodic table few elements that are chemically similar are placed in separate groups.

Multiple choice chemistry chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

If $Zn/Zn^{+2}$ electrode is diluted 100 times then the change in electromotive force will be :-

  1. increases of 59 mV

  2. decreases of 59 mV

  3. increases of 29.5 mV

  4. decreases of 29.5 mV
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Using the Nernst equation: E = E_cell - (0.059/n) * log(1/[Zn+2]). Diluting 100 times increases the concentration of the denominator in the log term, making the log term more negative, which increases the overall potential by (0.059/2) * log(100) = 0.059 V = 59 mV.

Multiple choice chemistry chemical effects of electric current applications of electrolysis electroplating extraction of metals by electrolysis

The process of depositing thin layer of a metal over an another metal with a help of electric current is called :

  1. electrorefining

  2. electroplating

  3. thermoplating

  4. none of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Electroplating is the process of plating one metal onto another, for decorative purposes or to prevent corrosion of a metal. 

Multiple choice chemistry chemical changes applications of electrolysis electroplating extraction of metals by electrolysis

Which pair of electrolytes could not be distinguished by the products of electrolysis using inert electrodes.

  1. $\text{1M CuSO} _4$ solution, $\text{1M CuCl} _2$ solution
  2. $\text{1M KCl}$ solution, $\text{1M Kl}$ solution
  3. $\text{1M AgNO} _3$ solution, $\text{1M Cu(NO} _3) _2$ solution
  4. $\text{1M KCl}$ solution, $\text{1M NaCl}$ solution
  5. $\text{1M CuBr} _2$ solution, $\text{1M CuSO} _4$ solution
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Electrolysis of 1M KCl and 1M NaCl using inert electrodes both yield potassium or sodium ions remaining in solution while hydrogen gas is evolved at the cathode and chlorine gas at the anode, making their electrolysis products identical and indistinguishable.