b. 1.0 M NaCl
c. 1.0 M AlCl3
d. 1.0 M BaCl2
The choices experiences colligative properties. These set of properties depend on the amount of solute dissolved in a solvent. These properties include freezing point depression, boiling point elevation, osmotic pressure and vapor pressure lowering. From the choices, the correct answer is A.
Answer : The correct option is, (C) 1.0 M
Explanation :
According to the relative lowering of vapor pressure, the vapor pressure of a component at a given temperature is equal to the mole fraction of that component of the solution multiplied by the vapor pressure of that component in the pure state.
1.0 M means that the 1.0 moles of solute present in 1 liter of solution.
Formula used :
where,
= vapor pressure of the pure component (water)
= vapor pressure of the solution
= mole fraction of solute
i = Van't Hoff factor
As we know that the vapor pressure depends on the mole fraction of solute and the Van't Hoff factor.
So, the greater the number of particles of solute dissolved the lower the resultant vapor pressure.
(a) The dissociation of 1.0 M is not possible because it is a non-electrolyte solute. So, the Van't Hoff factor will be, 1.
(b) The dissociation of 1.0 M will be,
So, Van't Hoff factor = Number of solute particles = = 1 + 1 = 2
(c) The dissociation of 1.0 M will be,
So, Van't Hoff factor = Number of solute particles = = 1 + 3 = 4
(c) The dissociation of 1.0 M will be,
So, Van't Hoff factor = Number of solute particles = = 1 + 2 = 3
From this we conclude that, 1.0 M has the highest Van't Hoff factor which means that the solution will exhibit the lowest vapor pressure.
Hence, the correct option is, (C) 1.0 M
When an uncharged pith ball is brought into the electrostatic field of a charged tod, the side of the pith ball closest to the negatively charged end of the rod will also gain a negatively charged surface. Then, it will not attract to the charged tod but rather it will repel.
I need the answer asap
Solid ➡ Liquid
Liquid ➡ Solid
Gas ➡ Solid
B. Soda mixed with the pizza sauce and sped up digestive enzyme activity.
C. Soda raised the pH in his stomach and sped up digestive enzyme activity.
D. Soda lowered the pH in his stomach and slowed digestive enzyme activity.
2. Which factor decreases the rate of a chemical reaction?
A. An inhibitor
B. A co-factor
C. Increased substrate
D. Cold temperature
3. Which component decreases the activation energy of a chemical reaction?
A. An inhibitor solution
B. Presence of an enzyme
C. Lower substrate concentration
D. Neutral pH levels
4. A biologist adds a vitamin solution to an enzyme/substrate solution that requires co-factors. What will happen to the substrate?
A. The vitamins will bond to the enzymes and increase their reactivity with the substrates.
B. The vitamins will bond to the enzymes and decrease their reactivity with the substrates.
C. The substrate molecules will bond to the vitamin molecules and inhibit bonding of the enzyme.
D. The substrate molecules will bond to the vitamin molecules and stimulate bonding of the enzyme.
5. Jennifer stews peaches to make peach jelly. She believes the homemade jelly will make a healthy treat full of vitamins and enzymes her body needs. Which of the following disproves her prediction?
A. The peaches don't contain enzymes.
B. The jelly has too much sugar to be healthy.
C. The enzymes in the peaches have denatured.
D. The vitamins in the peaches will inhibit the enzymes.
6. What statement best describes what happens during the catalytic cycle?
A. The enzyme breaks the substrate apart to prepare for the reaction.
B. The enzyme positions the substrate to increase access during a reaction.
C. The substrate uses enzyme energy to start the reaction.
D. The active site releases the substrate and replaces it with an inhibitor.
Answer 1) Option D) Soda lowered the pH in his stomach and slowed digestive enzyme activity.
Explanation : Consuming soda after eating pizza lowered the pH of the stomach which consequently, slowed the digestive enzyme activity in the stomach. The enzymes actively digest the food only in highly acidic environment.
Answer 2) Option A) An inhibitor
Explanation : An inhibitor is a substance usually added to a progressing chemical reaction to decrease the rate of reaction and finally stop the reaction.
Answer 3) Option B) Presence of an enzyme
Explanation : When an enzyme is added to a chemical reaction it is often seen that it lowers the energy of activation and catalyzes the reaction. So, enzyme acts as a catalyst and increases the reaction rate.
Answer 4) Option A) The vitamins will bond to the enzymes and increase their reactivity with the substrates.
Explanation : When the biologists adds a vitamin solution to an enzyme or a substrate solution the bonding will take place between vitamins and enzymes and as a result it will increase the reactivity of the substrates.
Answer 5) Option C) The enzymes in the peaches have denatured.
Explanation : When enzymes are stewed or rather boiled they become denatured and the bonds between them breaks, which makes the enzyme useless. Hence, proteins should be eaten raw without boiling at higher temperatures.
Answer 6) Option A) The enzyme breaks the substrate apart to prepare for the reaction.
Explanation : In a catalytic reaction the enzymes usually break the substrate and create more surface area for the reaction to occur.
B. Solids are high in density and compressible.
C. Solids are low in density and incompressible.
D. Solids are high in density and incompressible.
Answer: Option (D) is the correct answer.
Explanation:
Solids are the substances whose molecules are closely packed together due strong inter molecular forces between them. This causes the solid to have a fixed shape and volume.
Whereas density is mass divided by per unit volume.
Mathematically, Density =
Since, density is proportional to mass. So, more is the mass that is, more is the number of molecules held together by strong forces more will be its density.
Therefore, we can conclude that the statement solids are high in density and incompressible, best describes solids.