All categories

2 years ago

An aqueous solution is 0.387 m in hcl. what is the molality of the solution if the density is 1.23 g/ml?

1 answer:

8 0

Assume you have 1.00 L (1000 mL) of solution. d = m / V m = d x V = 1.23 g/mL x 1000 mL = 1230 g of solution 0.387 mol/L x 1 L = 0.387 mol HCl 0.387 mol HCl x (36.5 g / 1 mol) = 14.1 g HCl mass of water = 1230 g solution - 14.1 g HCl = 1216 g H2O = 1.216 kg H2O molality = mol HCl / kg water = 0.387 mol / 1.216 kg = 0.318 mol/kg (or 0.318 molal)

You might be interested in

Give the product for the reaction of 1-butene with methanol in the presence of acid. The mechanism is the same as the mechanism

Nuetrik [128]

Answer:

The final result is 2-methoxybutane.

Explanation:

1-butene has a carbon-carbon double bound between C1 and C2.

When it will react with methanol, in the presence of an acid, the result will be an ether.

C4H8 + CH3OH → C5H12O

An acid-catalyzed ether synthesis from alkenes is limited by carbocation stability.

In the first step, the double bound will disappear. The C2 atom will be a C+ atom, this becaus it has only 3 bounds and not 4.

This C+ -atom will atract the O- atom to form an ether. The CH3 of methanol will bind on the C3 atom, this is the most stable position.

2-methoxybutane will be formed. It has a structural formula of C5H12O

1-methoxybutane will not be formed, because it's less stable.

1-butanol will be formed when water is added to 1-butene. The mechanism has the same principle but not the same product.

1-ethoxybutane and 2-ethoxybutane have a structural formula of C6H14O, this will not be the final result.

The final result is 2-methoxybutane.

8 0

2 years ago

Methane and ethane are both made up of carbon and hydrogen. In methane, there are 12.0 g of carbon for every 4.00 g of hydrogen,

Sati [7]

Answer:

The answer is: Law of multiple proportions

Explanation:

The law of multiple proportions is a law of chemical combination given by Dalton in 1803.

According to this law, if more than one chemical compound is formed by combining two elements, then the mass of an element that combines with the fixed mass of other element is represented in the form of small whole number ratio.

Therefore, is an illustration of the law of the law of multiple proportions.

8 0

2 years ago

C2H5OH(aq) + MnO− 4 (aq) → Mn2+(aq) + CH3COOH(aq) of acetic acid from ethanol by the action of permanganate ion in acidic soluti

Andreas93 [3]

Answer :

Ethanol $(C_2H_5OH)$ act as reducing agent.

The smallest possible integer coefficient of $MnO_4^-$ in the combined balanced equation is, 4

Explanation :

Redox reaction or Oxidation-reduction reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.

Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. In this, oxidation state of an element increases. Or we can say that in oxidation, the loss of electrons takes place.

Reduction reaction : It is defined as the reaction in which a substance gains electrons. In this, oxidation state of an element decreases. Or we can say that in reduction, the gain of electrons takes place.

Reducing agent : It is defined as the agent which helps the other substance to reduce and itself gets oxidized. Thus, it will undergo oxidation reaction.

Oxidizing agent : It is defined as the agent which helps the other substance to oxidize and itself gets reduced. Thus, it will undergo reduction reaction.

The given chemical reaction is,

$C_2H_5OH(aq)+MnO_4^-(aq)\rightarrow CH_3COOH(aq)+Mn^{2+}(aq)$

The oxidation-reduction half reaction will be :

Oxidation : $C_2H_6O\rightarrow C_2H_4O_2$

Reduction : $MnO_4^-\rightarrow Mn^{2+}$

Now balance oxygen atom on both side.

Oxidation : $C_2H_6O+H_2O\rightarrow C_2H_4O_2$

Reduction : $MnO_4^-\rightarrow Mn^{2+}+4H_2O$

Now balance hydrogen atom on both side.

Oxidation : $C_2H_6O+H_2O\rightarrow C_2H_4O_2+4H^+$

Reduction : $MnO_4^-+8H^+\rightarrow Mn^{2+}+4H_2O$

Now balance the charge.

Oxidation : $C_2H_6O+H_2O\rightarrow C_2H_4O_2+4H^++4e^-$

Reduction : $MnO_4^-+8H^++5e^-\rightarrow Mn^{2+}+4H_2O$

In order to balance the electrons, we multiply the oxidation reaction by 5 and reduction reaction by 4 and then added both equation, we get the balanced redox reaction.

Oxidation : $5C_2H_6O+5H_2O\rightarrow 5C_2H_4O_2+20H^++20e^-$

Reduction : $4MnO_4^-+32H^++20e^-\rightarrow 4Mn^{2+}+16H_2O$

The balanced chemical equation in acidic medium will be,

$5C_2H_6O+4MnO_4^-+12H^+\rightarrow 5C_2H_4O_2+4Mn^{2+}+11H_2O$

In the redox reaction ethanol act as reducing agent and permanganate ion act as an oxidizing agent.

4 0

2 years ago

Gordon wrote this passage about mechanical waves for his physics class. But he got most of his facts mixed up. Only one sentence

Zinaida [17]

Answer: The correct answer is "Mechanical waves can apply pressure to and push on objects in their path".

Explanation:

Mechanical wave is wave in which there is an oscillation of the wave. The energy is transferred through a medium. Mechanical waves can apply pressure to and push on their path. Only the energy is transferred not the matter.

Mechanical waves are of three types: Transverse wave, Longitudinal wave and Surface wave. The examples of the mechanical wave are sound wave and water wave.

Sound is a pressure disturbance which travels through a medium. It consists of compression and rarefaction.

The mechanical waves need a medium for their propagation. They travel faster in denser medium.

Therefore, the correct option is (B).

4 0

2 years ago

Read 2 more answers

Aqueous hydrochloric acid reacts with aqueous sodium sulfite to produce aqueous sodium chloride and aqueous sulfurous acid. Writ

ohaa [14]

Answer:

2HCl(aq) + Na2SO3(aq) —> 2NaCl(aq) + H2SO3(aq)

Explanation:

HCl(aq) + Na2SO3(aq) —> NaCl(aq) + H2SO3(aq)

Let us balance the equation. This is illustrated below:

There are 2 atoms of Na on the left side of the equation and 1atom on the right side. It can be balance by putting 2 in front of NaCl as shown below:

HCl(aq) + Na2SO3(aq) —> 2NaCl(aq) + H2SO3(aq)

Now, we have 2 atoms of Cl on the right side and 1 atom on the left side. Thus, it can be balance by putting 2 in front of HCl as shown below:

2HCl(aq) + Na2SO3(aq) —> 2NaCl(aq) + H2SO3(aq)

A careful look at the equation proved that the equation is balanced as the numbers of the different atoms of the element on both side of the equation are the same.

4 0

2 years ago

Read 2 more answers