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3 years ago

Explain why pure hydrogen cyanide does not conduct electricity, but become a conductor when it is dissolved in water?

Chemistry

1 answer:

nlexa [21]3 years ago

8 0

Generally we have to kinds of conductors

a) metallic conductors: which conduct electricity due to free movement of electrons

b) electrolytic conductors: which conduct electricity due to movement of ions.

HCN is an electrolyte and is non conducting in pure state as it has no free ions or electrons

When HCN is dissolved in water it dissociates as

$HCN--->H^{+}(aq)+CN^{-}(aq)$

These ions obtained due to dissociation of HCN makes it conducting in nature.

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Write a balanced equation for the double-replacement neutralization reaction described, using the smallest possible integer coef

g100num [7]

Answer: The balanced chemical equation is given below.

Explanation:

Double-displacement reaction is defined as the reaction in which exchange of ions takes place. The general equation representing this reaction follows:

$AB+CD\rightarrow CB+AD$

The balanced chemical equation for the reaction of barium hydroxide and perchloric acid follows:

$Ba(OH)_2(aq.)+2HClO_4(aq.)\rightarrow Ba(ClO_4)_2(aq.)+2H_2O(l)$

By Stoichiometry of the reaction:

1 mole of barium hydroxide reacts with 2 moles of perchloric acid to produce 1 mole of barium chlorate and 2 moles of water molecule.

Hence, the balanced chemical equation is given above.

8 0

3 years ago

In acidic solution, the sulfate ion can be used to react with a number of metal ions. One such reaction is SO42−(aq)+Sn2+(aq)→H2

allsm [11]

Answer:

The final balanced equation is :

$SO_4^{2-}(aq)+4H^+(aq)+Sn^{2+}(aq)\rightarrow H_2SO_3(aq)+H_2O(l)+Sn^{4+}(aq)$

Explanation:

$SO_4^{2-}(aq)+Sn^{2+}(aq)\rightarrow H_2SO_3(aq)+Sn^{4+}(aq)$

Balancing in acidic medium:

First we will determine the oxidation and reduction reaction from the givne reaction :

Oxidation:

$Sn^{2+}(aq)\rightarrow Sn^{4+}(aq)$

Balance the charge by adding 2 electrons on product side:

$Sn^{2+}(aq)\rightarrow Sn^{4+}(aq)+2e^-$ ....[1]

Reduction :

$SO_4^{2-}(aq)\rightarrow H_2SO_3(aq)$

Balance O by adding water on required side:

$SO_4^{2-}(aq)\rightarrow H_2SO_3(aq)+H_2O(l)$

Now, balance H by adding $H^+$ on the required side:

$SO_4^{2-}(aq)+4H^+(aq)\rightarrow H_2SO_3(aq)+H_2O(l)$

At last balance the charge by adding electrons on the side where positive charge is more:

$SO_4^{2-}(aq)+4H^+(aq)+2e^-\rightarrow H_2SO_3(aq)+H_2O(l)$ ..[2]

Adding [1] and [2]:

$SO_4^{2-}(aq)+4H^+(aq)+Sn^{2+}(aq)\rightarrow H_2SO_3(aq)+H_2O(l)+Sn^{4+}(aq)$

The final balanced equation is :

$SO_4^{2-}(aq)+4H^+(aq)+Sn^{2+}(aq)\rightarrow H_2SO_3(aq)+H_2O(l)+Sn^{4+}(aq)$

4 0

3 years ago

What leads to the formation of gallstones?

marta [7]

An imbalance in the chemical make-up of bile inside the gallbladder.

3 0

3 years ago

6. In Reaction A, students are instructed to add no more than 0.25 mL of 15 M nitric acid. What volume of 15 M nitric acid is re

enyata [817]

The given question is incomplete, the complete question is:

In Reaction A, students are instructed to add no more than 0.25 mL of 15 M nitric acid. What volume of 15 M nitric acid is required to react with 0.030 g of copper metal? If 1.0 mL of acid contains approximately 20 drops, how many drops of nitric acid are needed?

Answer:

The correct answer is 0.0629 ml and 1.26 drops.

Explanation:

Based on the given question, the equation is:

Cu + 2HNO₃ (aq) ⇒ Cu(NO₃)₂ + H₂

The mass of copper given is 0.030 grams.

The molecular mass of copper is 63.55 gram per mole. The number of moles can be determined by using the formula, n = weight/molecular mass.

Moles of Cu = 0.030 grams/63.55 grams per mole = 0.000472 moles

Based on the reaction, it is clear that 1 mole of Cu reacts with 2 moles of nitric acid, therefore, the number of moles of nitric acid needed will be,

= 0.000472 mol Cu × 2 mol HNO₃ / 1 mole Cu

= 0.000944 mol HNO₃

The concentration of HNO₃ given is 15 M

Now the volume of HNO₃ required to react with 0.030 grams of copper metal will be,

Volume = 0.000944 mol HNO₃ × 1L/15 mol HNO₃ × 1000 ml/ 1L

= 0.0629 ml.

Based on the given information, if 1 ml of nitric acid comprise 20 drops, therefore, 0.0629 ml of the acid will require the drops,

Number of drops of HNO₃ = 0.0629 ml × 20 drops / 1 ml

= 1.26 drops.

7 0

3 years ago

Which substance cannot be broken down by a chemical change?

Marta_Voda [28]

Zirconium cannot be broken down by a chemical change, because it is an element. The others are all molecules. Hope ive helped :)

3 0

3 years ago

Read 2 more answers