Chemistry High School

Easyyyyy plz ...................

Permanent hardness of water is caused by dissolved :-
A) CaCl
B) Ca(HCO3)2
C) Mg(HCO3)2
D) NaOH​

Answers

Answer 1

Answer:

The answer is B

Explanation:

Answer 2

Answer:

Hello!

Your answer is B) Ca(HCO3)2!!

Explanation:

Hope this helps you!!

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Related Questions

Volume occupied 3.52x10^32 moluchles
of Mathane (CH4)
1) At STP​

Answers

Answer:

volume = 13097674418.528dm³

Explanation:

n = (3.52)*10^32/(6.02)*10^23)

n = (584717607.97)

n = volume /molar volume

molar volume at stp = 22.4dm³

volume= 584717607.97 x 22.4

volume = 13097674418.528dm³

A substance is said to hygroscopic if it
absorbs
(a) Carbon (IV) oxide from the atmosphere
(b) from the surrounding
(c) Moisture from the atmosphere to form
a solution
(d) Moisture from the atmosphere without
dissolving in it.​

Answers

The answer is the Letter D

An investigator proposes a study to determine the clinical relevance of a new assay technique to measure minimal residual disease (MRD) in adolescent (age 14-16) cancer patients undergoing chemotherapy. The study requires that two additional bone marrow aspirates be performed during the course of chemotherapy. The subject's chemotherapy will not be altered based on the results of the assay technique measures. However, future patients with cancer would benefit from improved interventions based on study findings. The IRB determined that the activity was a minor increase over minimal risk. Which of the following statements best describes the IRB approval requirements for involving adolescent cancer patients in the research study?

Assent is not required, however, both parents must give permission for the inclusion of the adolescent child.
Assent of the child only is required.
Assent is not required, however, one parent must give permission for the inclusion of the adolescent in this study.
Assent of the child and permission of both parents are required.

Answers

The correct answer is D. Assent of the child and permission of both parents are required.

Explanation:

In any research study, it is required to ask for the assent of the participants, no matter if the risk is low, which is established by the Institutional Review Board or IRB that regulates ethics in research. This implies in the case presented, the assent of the child is necessary, especially because a medical procedure (additional bone marrow aspirates) will be performed, and this is related to risks.

Besides this, if the participant is a minor the permission of both parents or the legal is needed as the child might not have the maturity to decide whether to participate in the research study. Thus, the requirements are " Assent of the child and permission of both parents are required".

The closeness of particles of gas and their low speeds allow intermolecular forces to become important at certain pressures and temperatures. Which best describes this statement? This is a limitation of the kinetic-molecular theory. This is a postulate of the kinetic-molecular theory. This describes ideal gas behavior using the kinetic-molecular theory. This describes ideal gas behavior without the kinetic-molecular theory.

Answers

This is a limitation of the kinetic-molecular theory. Hence, option A is correct.

What are intermolecular forces?

Strong intermolecular force is defined as the increase in viscosity of the liquid, increase in surface tension, decrease in vapour pressure, and an increase in the boiling point while weak intermolecular forces define as the decrease in viscosity, a decrease in surface tension, an increase in vapour pressure, and an increase in boiling point.

The closeness of particles of gas and their low speeds allow intermolecular forces to become important at certain pressures and temperatures which is a limitation of the kinetic-molecular theory.

Hence, option A is correct.

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The closeness of particles of gas and their low speeds allow intermolecular forces to become important at certain pressures and temperatures. This is a Limitation of the Kinetic Molecular Theory. Hence Opton (A) is correct.

What is Kinetic Molecular Theory of the Gases ?

According to the kinetic molecular theory, the average kinetic energy of gas particles is proportional to the absolute temperature of the gas.

The kinetic theory of gases is a simple, historically significant classical model of the thermodynamic behavior of gases, with which many principal concepts of thermodynamics were established.

Therefore, The closeness of particles of gas and their low speeds allow intermolecular forces to become important at certain pressures and temperatures. This is a Limitation of the Kinetic Molecular Theory. Hence Opton (A) is correct.

Learn more about Kinetic Molecular theory of the gasease here ;

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What period is Pb (lead) in?
O A. 14
O B. 6
O C. 4
O D. 5

Answers

The answer to the question is B

Answer:

[tex]\boxed{6}[/tex]

Explanation:

Lead Pb is an element in group 14 and period 6 in the periodic table.

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