All categories

2 years ago

Determine the mass in grams of 3.00 × 10²¹ atoms of arsenic. (The mass of one mole of arsenic is 74.92 g.)

Chemistry

1 answer:

Tpy6a [65]2 years ago

3 0

Answer:

The answer to your question is: 0.373 g

Explanation:

Data

mass = ? g

atoms = 3 x 10 ²¹

AM = 74.92 g

Process

1 mol of As ------------------ 6.023 x 10²³ atoms

x ------------------ 3 x 10 ²¹ atoms

x = 4.98 x 10⁻³ moles

1 mol ------------------------ 74.92 g

4.98 x 10⁻³ moles------- x

x = (4.98 x 10⁻³ x 74.92)/1

x = 0.373 g of As

You might be interested in

You are eating a pizza. What type of mixture are you consuming?

Hitman42 [59]

Answer:

Explanation:

Cheese, Meat, dough, Sauce

3 0

2 years ago

Read 2 more answers

In the Acid-Base Chemistry Experiment the measurement of pH will be used to explore acid-base concepts, analyze an unknown, and

aleksley [76]

Answer

a) A solution with a hydronium molarity of 0.00045 is acidic. True

Doing the calculus of pH

$pH= -Log [H^{+}] = -Log (0.00045)$

b) pH is a way to express the hydronium concentration over a wide range. True

pH means –Log[H+] and this value is used to express a wide range of hydronium concentration sometimes obtaining pH minor than zero.

c) Percent K and Fe are determined by doing ion exchange then a pH titration. False

Usually, Fe is determined by redox titration with potassium permanganate due to it’s more accurate. On the other hand, K is determined usually by volumetric process which includes precipitation like potassium picrate precipitate

d) About 0.2M HCl is the reagent used for the pH titrations. False.

In order to do pH titration, it is possible to use a wide range of HCl concentrations and other acids as reagent if the analyte is a basic compound. Otherwise, if the analyte is an acid compound you should use a basic compound as reagent.

e) A Lewis base is specie that can donate a proton to an acid. False

A Lewis base is an electron pair donor.

5 0

2 years ago

175 mL of Cl2 gas is held in a flexible vessel at

Gnoma [55]

Answer:

V₂ = 15.6 L

Explanation:

Given data:

Initial volume = 175 mL (0.175 L)

Initial pressure = 1 atm

Initial temperature = 273 K

Final temperature = -5°C (-5+273 = 268 K)

Final volume = ?

Final pressure = 1.16 kpa (1.16/101=0.011 atm)

Formula:

P₁V₁/T₁ = P₂V₂/T₂

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

Solution:

V₂ = P₁V₁ T₂/ T₁ P₂

V₂ = 1 atm × 0.175 L × 268 K / 273 K × 0.011 atm

V₂ = 46.9 L / 3.003

V₂ = 15.6 L

7 0

2 years ago

Read 2 more answers

According to Newton's Third Law, what is the equal and opposite force to the downward force of gravity pulling on a man standing

KIM [24]

Answer: Option (A) is the correct answer.

Explanation:

Newton's third law states that when one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.

In short we can say that every action has an equal and opposite reaction.

For example, when we hit a wooden table hardly with our hands then we are applying a force on the table and on the other hand table is applying a force in the opposite direction on our hand due to which we get hurt.

Therefore, when force of gravity pulls the man in downward direction then man pulling upward on the earth is applying a force in opposite direction of gravitational pull.

6 0

2 years ago

For the reaction A + B − ⇀ ↽ − C + D A+B↽−−⇀C+D , assume that the standard change in free energy has a positive value. Changing

AURORKA [14]

Answer:

a. Not change the free energy value

b. Increase the free energy value

c. Decrease the free energy value

d. Decrease the free energy value

Explanation:

a. Adding a catalyst:

A catalyst is a substance that will reduce the activation energy of a reaction, it means that the reaction will occur fast. The values of enthalpy, entropy, and free energy are not affected by a catalyst, so ΔG remains the same.

b. Increasing [C] and [D]:

For a reversible reaction, the value of free energy can be calculated by:

ΔG = ΔG° + RT*lnK

Where ΔG° is the standard value for free energy, R is the gas constant, T is the temperature, and K is the constant of equilibrium, which in this case:

K = ([C]*[D])/([A]*[B])

When [C] and [D] increase, the value of K increases, and lnK also increases, then, the value of ΔG increases.

c. Coupling with ATP hydrolysis:

The free energy can be calculated by:

ΔG = ΔH - TΔS

Where ΔH is the change in enthalpy, and ΔS the change in entropy. The ATP hydrolysis is an exothermic reaction, so ΔH <0. When it is coupled, it will reduce the total value of ΔH, and because of that, the value of ΔG will decrease.

d. Increasing [A] and [B]:

As explained above, the increasing at [A] and [B] will decrease the value of K, so the value of lnK will decrease, and ΔG value will also decrease.

4 0

2 years ago

Read 2 more answers