What is the correctly balanced chemical equation for the reaction of KOH and H2SO4

How many grams of calcium are made up by 2.68 x 1023 atoms?

raketka [301]

Answer:

Mass = 17.8 g

Explanation:

Given data:

Number of atoms of Ca = 2.68 × 10²³

Mass in gram = ?

Solution:

Avogadro number:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ atoms

2.68 × 10²³ atoms × 1 mole /6.022 × 10²³ atoms

0.445 mol

Mass in gram;

Mass = number of moles × molar mass

Mass = 0.445 mol × 40 g/mol

Mass = 17.8 g

5 0

3 years ago

If you ingest a chemical from lab, immediately drink plenty of milk, then contact your instructor and wait for his/her response.

GalinKa [24]

Answer:

False

Explanation:

The correct answer would be false.

If a chemical is ingested while working in the lab, the correct thing to do would be to contact the lab instructor right away as eating or drinking of any kind is prohibited in the laboratory.

While drinking milk may help in some cases depending on the nature and amount of the chemical ingested, only the lab instructor has the technical know-how to analyze the situation and administer first aids. Milk has the capacity to act as a buffer in some cases pending the time the victim would be able to get adequate medical attention.

6 0

3 years ago

Consider the following system at equilibrium: 2A(aq)+2B(aq)⇌5C(aq) Classify each of the following actions by whether it causes a

Alexandra [31]

Answer:

Rightwardshift: (a), (b), (f) and (h)

Leftwardshift: (c), (d), and (e)

No shift: (g)

Explanation:

1. Balanced chemical equation (given):

$2A(aq)+2B(aq)\rightleftharpoons 5C(aq)$

2. Equilibrium constant

The equilibrium constant is the ratio of the product of the concentrations of the products, at equilibrium, each raised to its stoichiometric coefficient, to the product of the concentrations of the reactants, at the equilibrium, each raised to its stoichiometric coefficient.

$K_{c}=\frac{[C(aq)]^5}{[A(aq)]^2\cdot [B(aq)]^2}$

a. Increase [B]

Rightward shift

Since, by assumption, the temperature of the reaction is the same, the equilibrium constant $K_{c}$ is the same, meaning that an increase in the concentration of the species B must cause a rightward shift to increase the concentration of the species C, such that the ratio expressed by the equilibrium constant remains unchanged.

b. Increase [A]

Rightward shift.

This is exactly the same case for the increase of [B], since it is in the same side of the equilibrium chemical equation.

c. Increase [C]

Leftward shift.

C is on the right side of the equilibrium equation, thus, following Le Chatelier's principle, an increase of its concentration must shift the reaction to the left to restore the equilibrium. Of course, same conclusion is drawn by analyzing the expression for $K_{c}$ : by increasing the denominator the numerator has to increase to keep the same value of $K_{c}$

d. Decrease [A]

Leftward shift.

This is the opposite change to the case {b), thus it will cause the opposite effect.

e. Decrease[B]

Leftward shift.

This is the opposite to case (a), thus it will cause the opposite change.

f. Decrease [C]

Rightward shift.

This is the opposite to case (c), thus it will cause the opposite change.

g. Double [A] and reduce [B] to one half

No shift

You need to perform some calculations and determine the reaction coefficient, $Q_c$ to compare with the equilibrium constant $K_{c}$ .

The expression for $Q_c$ has the same form of the equation for $K_{c}$ . but the it uses the inital concentrations instead of the equilibrium concentrations.

$Q{c}=\frac{[C(aq)]^5}{[A(aq)]^2\cdot [B(aq)]^2}$

Doubling [A] and reducing [B] to one half would leave the product of [A]² by [B]² unchanged, thus $Q_c$ will be equal to $K_{c}$ .

When $Q_c$ = $K_{c}$ the reaction is at equilibrium, so no shift will occur.

h. Double both [B] and [C]

Rightward shift.

Again, using the expression for $Q_c$ , you will realize that the [C] is raised to the fifth power (5) while [B] is squared (power 2). That means that $Q_c$ will be greater than $K_{c}$ ..

When $Q_c$ > $K_{c}$ the equilibrium must be displaced to the left some of the reactants will need to become products, causing the reaction to shift to the right.

Summarizing:

Rightwardshift: (a), (b), (f) and (h)

Leftwardshift: (c), (d), and (e)

No shift: (g)

4 0

4 years ago

Strong hydrochloric acid can dissolve many substances. Which type of hazardous waste would this acid be?

KonstantinChe [14]

Answer:

C. Corrosive waste

Explanation:

Hydrochloric acid is formed when hydrogen chloride gas is dissolved in water. The gas is toxic when inhaled and dissolves very readily in water to form the acid.

Hydrochloric acid is a strong acid as it ionizes completely in aqueous solutions to produce chloride ions and hydronium ions.

The concentrated acid is very corrosive in that it dissolves many other substances. Therefore, great care must be taken when handling the concentrated form of the acid.

It poses an environmental hazard due to its corrosive nature. Also, in industries and science laboratories, concentrated hydrochloric acid can corrode metal pipes and should not be drained into pipes without first being diluted.

However, the acid is very important in many industrial as well as laboratory procedures.

4 0

3 years ago

Mathematical Skills for the Physical Sciences: Tutorial

blondinia [14]

Answer:

total disance covered by car=2858.11 meters

Explanation:

First calculate the time for which the given energy can be used

total energy=52700 joules;

756 joules used in every second;

$Total time=\frac{52700joules}{756joules/sec}$