Calculate the density (in g/mL) of a liquid that has a mass of 0.115g and a volume of 0.000265 L

Which one of the following processes produces a decrease in the entropy of the system?a, precipitation of AgCl(s) from Ag+(aq) a

Usimov [2.4K]

Answer: precipitation of $AgCl(s)$ from $Ag^+(aq)$ and $Cl^-(aq)$ ions in solution

Explanation:

Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa.

$\Delta S$ is positive when randomness increases and $\Delta S$ is negative when randomness decreases.

a) precipitation of $AgCl(s)$ from $Ag^+(aq)$ and $Cl^-(aq)$ ions in solution : As ions are getting solidified, entropy decreases.

b) dissolution of $LiOH(s)$ in water: The compounds dissociates into ions, entropy increases.

c) melting solid gold into liquid gold: The randomness increases, entropy increases.

d) evaporation of Hg(l) to form Hg(g) : The randomness increases, entropy increases.

e) mixing of two gases into one container : The randomness increases, entropy increases.

4 0

3 years ago

Calcium carbide reacts with water to produce acetylene gas according to the following equation: CaC2(s) + 2H2O(l)C2H2(g) + Ca(OH

poizon [28]

Answer:

33.7

Explanation:

i just know i had a question on it'

7 0

3 years ago

What are columns on the periodic table called? What is the significance of the columns on the periodic table?

chubhunter [2.5K]

Answer:

The vertical columns of the periodic table are called groups, or families. The significance is elements with similar properties are placed in the same vertical columns. The horizontal rows of the periodic table are called periods. The significance is that properties vary from left to right along the rows.

Explanation:

We just did this in science

3 0

3 years ago

Read 2 more answers

Plz give me short note on isotopes in agriculture industries and medicine

Mumz [18]

Uses of isotopes:

In agriculture,

C-14 is used to trace the path of photosynthesis.

In medicine,

Iodine -131 is used in the treatment of

goiter

8 0

3 years ago

A 0.879 g sample of a CaCl2 ∙ 2 H2O / K2C2O4 ∙ H2O solid salt mixture is dissolved in 150 mL of deionized water. A precipitate f

Alecsey [184]

Answer:

a. CaCl₂.2 H₂O (aq) + K₂C₂O₄. H₂O (aq) ----> 2 KCl + CaC₂O₄ (s) + 3 H₂0 (l)

b. Ca²+ (aq) + C₂O₄²- (aq) ----> CaC₂O₄ (s)

C. moles of CaCl₂.2 H₂O reacted in the mixture = 0.00222 moles

d. Mass of CaCl₂.2 H₂O reacted = 0.326 g

e. Moles of K₂C₂O₄.2 H₂O reacted = 0.00222 moles

f. Mass of K₂C₂O₄.H₂O reacted = 0.408 g

g. mass of K₂C₂O₄.H₂O remaining unreacted = 0.145 g

h. Percent by mass CaCl₂.2 H₂O = 37.1%

Percent by mass of K₂C₂O₄.H₂O = 62.9%

Explanation:

a. Molecular equation of the reaction is given below :

CaCl₂.2 H₂O (aq) + K₂C₂O₄. H₂O (aq) ----> 2 KCl + CaC₂O₄ (s) + 3 H₂0 (l)

b. The net ionic equation is given below

Ca²+ (aq) + C₂O₄²- (aq) ----> CaC₂O₄ (s)

C. mass CaC₂O₄ produced = 0.284 g, molar mass of CaC₂O₄ = 128 g/mol

moles CaC₂O₄ produced = 0.284 g / 128 g/mol = 0.00222 moles

Mole ratio of CaC₂O₄ and CaCl₂.2 H₂O is 1 : 1, therefore moles of CaCl₂.2 H₂O reacted in the mixture = 0.00222 moles

d. Mass of CaCl₂.2 H₂O reacted in the mixture = number of moles × molar mass

Molar mass of CaCl₂.2 H₂O = 147 g/mol

Mass of CaCl₂.2 H₂O reacted = 0.00222 moles × 147 g/mol = 0.326 g

e. Mole ratio of K₂C₂O₄.2 H₂O and CaC₂O₄ is 1 : 1, therefore, moles of K₂C₂O₄.2 H₂O reacted = 0.00222 moles

f. Mass of K₂C₂O₄.H₂O reacted in the mixture = number of moles × molar mass

Molar mass of K₂C₂O₄.H₂O = 184 g/mol

grams K2C2O4-H2O reacted = 0.00222 moles 184 g/mole = 0.408 g

g. Mass of sample = 0.879 g

mass of CaCl₂.2 H₂O in sample completely used up = 0.326 g

mass of K₂C₂O₄.H₂O in sample = 0.879 g - 0.326 g = 0.553 g

mass of K₂C₂O₄.H₂O remaining unreacted = 0.553 g - 0.408 g = 0.145 g

h. Percent by mass CaCl₂.2 H₂O = 0.326 /0.879 x 100% = 37.1%

Percent by mass of K₂C₂O₄.H₂O = 0.553/0.879 × 100% = 62.9%

6 0

3 years ago