Why do we test for free chlorine in drinking water?

Answers

Answer 1

Answer:

The presence of free chlorine in drinking water is correlated with the absence of most disease-causing organisms, and thus is a measure of the potability of water


Related Questions


What is the formula mass of ZrF4?


Answers

Answer:

167.217g/mol

Explanation:

Formula mass is defined as the mass in grams that a mole of a molecule weighs. To solve the formula mass of ZrF₄ we require the molar mass of Zr and of F (Molar mass Zr: 91.225g/mol; F: 18.998g/mol)

In this molecule, there is 1 mole of Zr and 4 moles of F. The formula mass is:

Zr = 1*91.225g/mol = 91.225g/mol

F = 4*18.998g/mol = 75.992g/mol

Formula mass: 91.225g/mol + 75.992g/mol

167.217g/mol

Use the following chemical equation, how many moles of ammonia (NH 3 ) produced when 3.15 moles of nitrogen (N 2 ) reacts with hydrogen (H 2 ) ? N 2(g) + 3H 2(g) 2NH 3(g)

Answers

Answer:

[tex]n_{NH_3}^{produced}=6.3molNH_3[/tex]

Explanation:

Hello there!

In this case, according to the given chemical reaction, it is possible for us to use the 1:2 mole ratio of nitrogen to ammonia to calculate the moles of the latter that are produced when reacting 3.15 moles of the former with hydrogen as shown below:

[tex]n_{NH_3}^{produced}=3.15molN_2*\frac{2molNH_3}{1molN_2}[/tex]

Thus, by solving the equation we obtain:

[tex]n_{NH_3}^{produced}=6.3molNH_3[/tex]

Best regards!

What type of consumer eats only producers?

Answers

Answer: Primary consumers make up the second trophic level. They are also called herbivores. They eat primary producers—plants or algae—and nothing else. For example, a grasshopper living in the Everglades is a primary consumer

Answer:

primary consumer make up the second trophic level .they are also herbivores they eat primary consumer plants or alger and nothing else .for example a grasshopper living in the everglades is a primary consumer

Pure gold has a density of 19.3 g/cm³. if it is made into a crown. what will be the density of the crown? how can you find out if the crown is indeed made of pure gold and nothing else?​

Answers

Answer:

19.3g cm^3

If it deviates from the original 19.3g cm^3

oi oi oi oi ewin
.................

Answers

Muy bein me gusta hope this makes you smile

12. Which organelle is found in plant and animal cells and is involved in making cellular energy from
respiration?

Answers

Answer:

The mitochondria is the organelle found in plant and animal cells and is involved in making cellular energy from respiration.

Explanation:

Can you all go vote for Dacia Campbell for Brainly Educator of The Year!!!!!
It would mean a ton!!! Plus, I'll give your profile a big THANK YOU...I'll give Brainliest and you get 50 points! Please, please, please. Go vote for her!

Answers

Answer:

i voted her!!!!

Explanation:

CHEMISTRY HELP ASAP
Use this balanced equation for the two questions below:
2KClO3(s) → 2KCl(s) + 3O2(g)
9. How many moles of KClO3 are used to produce 9.9 moles of O2?

10. How many moles of O2 are produced from 11.2 moles of KClO3?

PLS SHOW WORK TOO THX

Answers

Answer:

1 mole of KClO_3 contains 3 moles of O.

10 moles of O_2 contains 20 moles of O.

You need 20/3 moles of KClO_3 to produce 10 moles of O_2

Explanation:

sana makatulong

temperature usually increase when water condenses which behavior of water is most directly responsible for this phenomenon?

Answers

Answer:

Temperature usually increases when water condenses. What behavior of water is most directly responsible for this phenomenon? The release of heat by the formation of hydrogen bonds. Hydrogen bonds stabilize and keep the of ice farther apart than the water molecules of liquid water.

Which is least likely to occur after an experiment is conducted to a test a hypothesis?
The data is analyzed to see if it supports or refutes the hypothesis.
• The same experiment is conducted again to see if the data are reliable.
The hypothesis becomes a theory if the results support it.
O A new experiment is designed to provide additional data about the hypothesis.

Answers

Answer:

4th one. (A new experiment is designed to provide additional data about the hypothesis.)

Answer:

The correct answer is C)The hypothesis becomes a theory if the results support it.

Explanation:

A solution is prepared by dissolving 0.23 mol of hypochlorous acid and 0.27 mol of sodium hypochlorite in water sufficient to yield 1.00 L of solution. The addition of 0.05 mol of HCl to this buffer solution causes the pH to drop slightly. The pH does not decrease drastically because the HCl reacts with the ________ present in the buffer solution. The Ka of hypochlorous acid is 1.36 × 10-3.

Answers

Answer:

hypochlorite ion

Explanation:

The hypochlorous acid, HClO, is a weak acid with Ka = 1.36x10⁻³, when this acid is in solution with its conjugate base, ClO⁻ (From sodium hypochlorite, NaClO) a buffer is produced. When a strong acid as HCl is added, the reaction that occurs is:

HCl + ClO⁻ → HClO + Cl⁻.

Where more hypochlorous acid is produced.

That means, the HCl reacts with the hypochlorite ion present in solution

A tree can be a _________________________ for insects in a schoolyard.

Answers

Answer:

habitat/shelter

Explanation:

witch are the two factors decrease as the kinetic energy of the particles in an object decreases

Answers

Answer:

mass and speed are the two factor

Which product is often derived from the natural environment?

Answers

Answer:

coal, cotton, chinese tradictional medicine

What is the Kc for the following reaction at equilibrium at 800∘C if [CO2]= 0.030 M ? CaCO3(s)⇌CaO(s)+CO2(g)

Answers

Answer:

0.030

Explanation:

Step 1: Write the balanced reaction at equilibrium

CaCO₃(s) ⇌ CaO(s) + CO₂(g)

Step 2: Calculate the concentration equilibrium constant

The concentration equilibrium constant (Kc) is equal to the product of the concentrations of the products raised to their stoichiometric coefficients divided by the product of the concentrations of the reactants raised to their stoichiometric coefficients. It doesn't include solids or pure liquids.

Kc = [CO₂] = 0.030

What is the empirical formula for C6H12?

Answers

Answer:

The empirical formula of C6 H12,

how many grams of ammonia produced from 1000 grams of N2?

Answers

Answer:

N2 + 3H2 ———> 2NH3

As we know 1000 grams ammonia is 58.82 moles so according to unitary method,

2 mole NH3 formed by 1 mole N2 hence 58.82 NH3 will be given by 29.41 moles N2.

No. Of moles = given mass/molar mass

Implies that

Mass of nitrogen required = 29.41*28 = 823.48 grams.

Explanation:

How many grams of H2SO4 will react 650.0 grams of NaOH?

Answers

Answer:

H2SO4 + 2NAOH➡NA2SO4+2H2O

H2SO4 = 1*2 +32+16*3= 98g

NAOH = (11+16+1)=28

Explanation:

To calculate the number of Mole = Mole *Molar Mass

To calculate for gram = Mole/ Molar Mass

20.5g NaoH/1 * 1 mole NaOH/28g NaoH = 0.73M NaoH

0.73M NaoH /1 * 1 M H2SO4 /2M NaoH = 0.37M H2SO4

0.37 M H2SO4 /1 * 98g H2SO4 /1M H2SO4 = 0.00367g H2SO4

:- 0.00367g of Sulphuric Acid will be needed to complete the reaction.

What is the greatest concentration of pollution

Answers

Answer:

B

Explanation:The poisonous substances, present in the environment can easily get into the trophic level as living organism depends on each other and environment for food and nutrition. These poisonous substances may not be broken down in the body or excreted easily, efficiently and quickly. Instead, they accumulate in the tissues, and as the living organism eats more, the concentration of these substances increases and they pass from one trophic level to the next. The tertiary consumer being at the top of trophic levels receives the maximum pollutant. This phenomenon is known as biological magnification.

So, the correct answer is option B.

A(n) _________ is an atom or a group of atoms with either a positive or negative charge
O compound
O ion
O molecule
O nucleus

Answers

Answer:

the answer is ion..

hope it helps..

The sender for this question would be ion.


1 Write the chemical symbols for following elements: Nitrogen-
Phosphorus- bromine- Zinc-Potassium-Magnesium.

Answers

Answer:

Look below

Explanation:

Nitrogen: N

Phosphorus: P

Bromine: Br

Zinc: Zn

Potassium: K

Magnesium: Mg

Hope this helps(would be very grateful if you mark this answer branliest bc i need for lvl up)

Need help with this question please.

Answers

Answer:

12.8

Explanation:

14 = pOH + pH

pH = 14 - pOH

pH = 14 - 1.2

pH = 12.8

Last time I'm asking this, answer, this time, 50 points.
Think about a single cell and its parts; for example, think about a cell inside the human body. Now, select an everyday object that could be used as a model for a cell and its parts. In words and/or pictures, describe your model and how it is like the cell.

Answers

Explanation:

Well i mean clothes so cells make tissues which help organs clothes can technically help you if you fall it has layers so it woulf be as a cell?

Calculate the pH when 64.0 mL of 0.150 M KOH is mixed with 20.0 mL of 0.300 M HBrO (Ka = 2.5 × 10⁻⁹)

Answers

Answer:

The answer is "12.06"

Explanation:

Given:

[tex]M(HBrO) = 0.3\ M\\\\V(HBrO) = 20 \ mL\\\\M(KOH) = 0.15 \ M\\\\V(KOH) = 64 \ mL[/tex]

[tex]\to mol(HBrO) = M(HBrO) \times V(HBrO) = 0.3 M \times 20 mL = 6 \ mmol\\\\\to mol(KOH) = M(KOH) \times V(KOH)= 0.15 M \times 64 mL = 9.6 mmol[/tex]

  6 mmol of both will react

excess KOH remaining[tex]= 3.15 \ mmol[/tex]

Volume[tex]= 20 + 64 = 84 \ mL[/tex]

[tex][OH^{-}] = \frac{ 9.6 \ mmol}{84\ mL} = 0.01142\ M[/tex]

use:

[tex]pOH = -\log [OH^-][/tex]

        [tex]= -\log (1.142\times 10^{-2})\\\\= 1.94[/tex]

use:

[tex]PH = 14 - pOH[/tex]

       [tex]= 14 - 1.94\\\\= 12.06[/tex]

The pH of the resulting  solution is  12.63.

The equation of the reaction is;

HBrO(aq) + KOH(aq) ------> KOBr(aq) + H2O(l)

Number of moles of KOH= 64/1000 × 0.150 M = 0.0096 moles

Number of moles of HBrO = 20/1000 × 0.300 M = 0.0060 moles

Number of moles of excess base = 0.0096 moles -  0.0060 moles = 0.0036 moles

Total volume of solution = 64.0 mL +  20.0 mL = 84 mL = 0.084 L

Molarity of excess base =  0.0036 moles/0.084 L = 0.043 M

pOH = -log[OH-]

pOH = -log[ 0.043 M]

pOH = 1.37

pH + pOH = 14

pH = 14 -pOH

pH = 14 - 1.37

pH = 12.63

Learn more: https://brainly.com/question/11897796

Explain the difference between an exothermic and an endothermic reaction.

Answers

Answer:

Explanation:

Heat is a reactant.

If the equation requires heat to occur, the reaction is endothermic

The equation would have this model

A + B + heat =====> C + D

If the equation gives away heat, then it is exothermic

The equation would look like this. (I'll use a common reaction)

CH4 + 2O2 - heat ===> CO2 + 2H2O

The heat is minus when it has to be given away.

An alternating current complete 100 cycles in 0.1s. it's frequency is​

Answers

Answer:

The frequency is 1000 cycles/s

Explanation:

An alternating current is an electrical current in which the current changes its magnitude and the sense cyclically. The frequency of this current is defined as the cycles that the current completes in one second.

As the current completes 100 cycles in 0.1 seconds, the frequency is:

100 cycles / 0.1s = 1000 cycles /s

The frequency is 1000 cycles/s

For the following exothermic reaction system at equilibrium:
H2O(g) CO(g) CO2(g) H2(g)
Choose the changes that will increase the value of K.
a. Decrease the volume (constant T)
b. Add H2O(g) (constant T)
c. Remove H2(g) (constant T)
d. Add a catalyst (constant T)
e. Add CO2(g) (constant T)
f. Increase the temperature
g. Decrease the temperature

Answers

Answer:

See explanation.

Explanation:

Hello there!

In this case, for the chemical reaction:

[tex]H_2O(g) CO(g)\rightleftharpoons CO_2(g) H_2(g)[/tex]

It is widely known that the the only factor altering the equilibrium constant is the temperature because of its thermodynamic definition:

[tex]K=exp(-\frac{\Delta G(T)}{RT} )[/tex]

Which is temperature dependent on the denominator and on the Gibbs free energy of reaction. In such a way, the answers can be just f and g, as the other factors modify Q (reaction quotient) rather than K. Thus, we can discuss about f and g:

f. This would increase K if the Gibbs free energy of reaction is positive (nonspontaneous).

g. This would increase K if the Gibbs free energy of reaction is negative (spontaneous).

It is important to discuss those two because the Gibbs free energy is not given.

Regards!

Electrolysis is used in the electroplating of metals. The same amount of current is passed through separate aqueous solutions of CuSO4, Sn(SO4)2 and Cr2(SO4)3 in separate electrolytic cells for the same amount of time. State and explain which cell would deposit the greatest amount (in mol) of metal. Identify the electrode at which the metal is deposited.

Answers

Answer:

CuSO4 cell will have the greatest amount of deposit among all three. The deposit will occur at the cathode

Explanation:

The valence of the elements in this case is as follows -

Cu - 2e-

Sn - 4e-

Cr - 3e-

CuSO4 cell will have the greatest amount of deposit among all three

The atoms of copper metal will deposit at the cathode. At the cathode, the least number of moles of electrons needed .

Hence, more amount of copper  can be extracted out by the electrolyte

 

What is NaC2H3O2 coefficient

Answers

Answer:yes coefficient u mean??

Explanation:

Combine terms: 12a + 26b -4b – 16a.​

Answers

Answer:

= -4a+22b

Explanation:

i hope this helps :)

Answer:

12a-16a =-4a

26b -4b =22b

the final answer is-4a +22b

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