chất có ở đâu ? nước tự nhiên là chất hay hỗn hợp

Answers

Answer 1

Answer:

Water, H2O, is a pure substance, a compound made of hydrogen and oxygen. Although water is the most abundant substance on earth, it is rarely found naturally in its pure form. Most of the time, pure water has to be created. Pure water is called distilled water or deionized water.


Related Questions

Identify the products represented by letters A-F to complete each chemical equation, then write the net ionic equations for the reactions including the physical states of reactants and products. Use the standard enthalpies of formation to calculate the changes in the standard enthalpies of reaction.
a) NaOH(aq)+HCl(aq)⟶A(aq)+B(l)
A=

B=

Balanced net ionic equation:
Δ0rxn=


b) NaOH(aq)+NH4Cl(aq)⟶C(aq)+D(aq)+E(l)
C=
D=
E=
Balanced net ionic equation:
Δ0rxn=


c) HCl(aq)+NH3(aq)⟶F(l)
F=

Balanced net ionic equation:


Δ0rxn=

Answers

The product of a chemical reaction is what is remaining at the end of the reaction. The combination between reactant to form products can happen in a variety of ways including combination of ions in a solution to form new compounds

The correct compounds representing the variables and the net ionic equations are as follows:

a) A = NaCl

B = H₂O

Balanced net ionic equation: OH⁻(aq) + H⁺(aq) → H₂O (l)

ΔHrxn = Negative

b) C = NH₃

D = NaCl(aq)

E = H₂O(l)

Balanced net ionic equation: OH⁻(aq) + NH₄⁺(aq) → NH₃(aq) + H₂O(l)

ΔHrxn = Negative

c) F = NH₄Cl(aq)

Balanced net ionic equation: H⁺(aq) + NH₃(aq) → NH₄⁺(aq)

ΔHrxn = Negative

The reason the above values are correct are as follows:

a) Part (i)

The given chemical equation is

NaOH(aq) + HCl(aq) → A(aq) + B(l)

The chemical equation is the reaction between sodium hydroxide NaOH (aq) and hydrochloric acid HCl (aq), the product of the reaction is sodium chloride and water as follows;

NaOH(aq) + HCl(aq) → NaCl(aq) + H₂O(l) + Heat

Therefore, we have;

A = NaCl, and B = H₂O

Part (ii)

The ionic equation is given as follows;

Na⁺(aq) + OH⁻(aq) + H⁺(aq) + Cl⁻(aq) → Na⁺(aq) + Cl⁻(aq) + H₂O (l)

Given that Na⁺(aq) and Cl⁻(aq) are spectator ions in the reaction, we have the balanced net ionic equation given as follows;

Balanced net ionic equation: OH⁻(aq) + H⁺(aq) → H₂O (l)

Part (iii)

ΔHrxn = Negative

b) Part (i)

The given chemical equation is NaOH(aq) + NH₄Cl(aq) → C(aq) + D(aq) + E(l)

The given reaction is between sodium hydroxide, NaOH(aq) and ammonium chloride, NH₄Cl(aq) and the products of the reaction are dissolved ammonia NH₃(aq), sodium chloride NaCl(aq), and water H₂O(l)

Therefore, we have;

NaOH(aq) + NH₄Cl(aq) → NH₃(aq) + NaCl (aq) + H₂O(l) + Heat

Therefore;

C = NH₃, D = NaCl(aq), E = H₂O(l)

Part (ii)

The ionic equation for the reaction is given as follows;

Na⁺(aq) + OH⁻(aq) + NH₄⁺(aq) + Cl⁻(aq) → NH₃(aq) + Na⁺(aq) + Cl⁻(aq) + H₂O(l)

The Na⁺(aq) and Cl⁻(aq) occur in both the reactants and products, therefore, they cancel out as spectator ions and we have;

Balanced net ionic equation: OH⁻(aq) + NH₄⁺(aq) → NH₃(aq) + H₂O(l)

Part (iii)

ΔHrxn = Negative

c) Part (i)

HCl(aq) + NH₃(aq) → F(l)

The given reaction is between hydrochloric acid and aqueous ammonia which has the product as ammonium chloride, NH₄Cl

Therefore, the reaction is given as follows;

HCl(aq) + NH₃(aq) → NH₄Cl(aq) + Heat

∴ F = NH₄Cl(aq)

Part (ii)

The ionic equation is given as follows;

H⁺(aq) + Cl⁻(aq) + NH₃(aq) → NH₄⁺(aq) + Cl⁻(aq)

Therefore, the chlorine ion Cl⁻(aq) occurs in both the reactant and product and can therefore, can be canceled out, and we have;

Balanced net ionic equation: H⁺(aq) + NH₃(aq) → NH₄⁺(aq)

Part (iii)

ΔHrxn = Negative

Learn more about balanced net ionic equation here:

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What is 3 x 10^4 multiplied by 5 x 10^2?​

Answers

Answer:

15000000

Explanation:

30000 x 500=15000000. I believe... lemme know if I was wrong, hope this helps <3.

In the reaction 2H2 + O2 + H20, what coefficient should be placed in front of H2O to balance the reaction? 0 2 03 O 4​

Answers

Answer:

2

Explanation:

2×2

2O

soooo

2H2O means 4H2O

Which statements describe density? Check all that apply.

Density is a chemical property of an object.
The density of an object is constant.
Density is a derived unit of measure.
Density is the sum of the mass and volume of an object.
The density of an object determines whether it will sink or float.

( pick multiple)

Answers

Answer:

density is the sum of the mass and volume of an object

which equation is used to calculate the free energy change of a reaction

Answers

Answer:

B bcx is a way of separating different crystals from each other and the other is a way of separating different crystals from each other and the other

Can someone please help me​

Answers

Answer:

white

Explanation:

Facts, figures, and other evidence learned through observation are call

Answers

Answer:

Data

Explanation:

Data are the facts, figures, and other evidence gathered through observations.


Which TWO properties of water make it
essential for supporting the
development of life? (Again, there
are TWO answers here, be sure to check
both of them!
Water has all the ingredients needed to
create lite.
Water allows biomolecules (like proteins) to
move around and react with one another.
Life gets thirsty and needs to stay
hydrated.
EN
INTL
WS
Water helps regulate temperature so it
doesn't get too hot or too cold.
8
53

Answers

Answer:

oooooooooougifufofhhdykddykyd

• 1. An object has a mass of 570g and a volume of 2280ml. Calculate its
density. 250 kg/m3

Answers

Answer:

Density=mass/volume

= 570/2280

=0.25g/ml

If you can run 6km in 24 minutes, how many cm can you run in 5 hours?

Answers

Answer:

7500000cm/hr

Explanation:

6km=600000cm

24min=24/60hr=0.4hr

so, according to the question

6k/24km=600000cm÷0.4hr

=1500000cm/hr

therefore in 5 hours we can run:

5×1500000cm/Hr

=7500000cm/hr

A person can run "7,500,000 cm" in 5 hours.

According to the question,

A person can run 6 km in 24 minutes, i.e.,

= [tex]\frac{6}{24} \ km/min[/tex]

and,

5 hours = 300 minutes

then,

→  A person can run in 5 hours:

= [tex]\frac{6}{24}\times 300[/tex]

= [tex]\frac{1800}{24}[/tex]

= [tex]75 \ km[/tex]

By converting km into cm, we get

= [tex]7500000 \ cm[/tex]

So the above is the right answer.

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What is the Color of trioxonitrate(v)

Answers

Answer:

it's yellowish in color plz Mark me as brainliest

Answer:

It's a yellowish color like copper

What do we call planets that are not in our solar system

Answers

Exoplanets are the planets that are outside our solar system

Calculate the mass of a liquid with a density of 0.92g/ml and a volume of 15 ml

Answers

Answer:

13.8g

Explanation:

Remember that density is equal to mass over volume

d=m/v

rearrange the problem and you get dv=m

(0.92g/mL)(15mL)=13.8g

Which is larger?
1). 1 liter or 1500 milliliters
2) 12 cm or 12 milliliters

Answers

Answer:

1). 1 litre

2).12 cm

Explanation:

In 1 litre = 1000 ml whereas 1500 milliliters equals 0.15 litres and it is same for 12 cm and 12 milliliters

How should you add metal to the graduated cylinder so that it will not crack the glass at the bottom?
Get the metal as close to thn

Answers

Answer:

you tilt the cylinder at a slight angle so that the metal slides down the sides, rather than drops all it`s weight to the bottom

will mark brainliest if correct

Answers

Answer:

that would be B

Explanation:

PLEASE HELP ON EASY CHEMICAL PROPERTIES

Answers

Answer:

1, just I) color.

Explanation:

Physical properties are the properties that can be observed without changing the composition of a substance, such as color, temperature, density, and boiling point.

A physical change is a change in the substance that only modifies its aggregation state, such as solidification, and boiling.

Chemical properties are the properties that need a reaction to being observed, such as combustibility, which needs a combustion reaction to being quantified.

When a chemical reaction occurs, and the composition of the substance change, it's a chemical change.

So, heating copper with carbon is a chemical reaction, and purification by electrolysis is too. Color is the only physical property.

does the law of conservation apply to burning fossil fuels

Answers

Answer: yes

Explanation:

While burning fossil fuels energy is under going a chemical reaction but the matter/energy itself is not being destroyed or created

Answer:

The law of conservation applies to the burning fossil fuels

Explanation:

When you burn fossil fuels, some of the energy is transformed into other types of energy, and some of it is transferred to other objects, yet the energy is neither destroyed or created, so it applies to the law of conservation.

A sample of brass weighing 1.203g was analyzed. The zinc in the alloy was reacted with 35.123g of HCl in excess, according to the balanced equation:
Zn (s) + 2HCl(aq) - > H2(g) + ZnCl2 (aq)
After all the zinc reacted, the mass of the remaining solution weighed 36.309g

What was the mass of H2 produced?
What mass of Zn reacted?
What was the percentage of Zn (by mass) in the alloy?

Answers

The number of moles of reactants and products can be used to obtain the mass of products formed. The results obtained are as follows;

The mass of hydrogen produced is 0.0174 gramsThe mass of zinc produced is  0.5688 gramsThe percentage by mass of zinc in the brass alloy is 47.3 %

The question says that HCl was in excess. It means that after the reaction, we will have unreacted HCl(aq) and  ZnCl2(aq) in the remaining solution.

Hence;

Mass of ZnCl2(aq) formed = 36.309g - 35.123g  = 1.186g

Number of moles ZnCl2(aq) formed = [tex]\frac{mass of ZnCl2(aq) formed}{molar mass of ZnCl2}[/tex]

[tex]\frac{1.186g}{136.286 g/mol}[/tex] = 0.0087 moles

From the reaction equation;

[tex]Zn (s) + 2HCl(aq) - > H2(g) + ZnCl2 (aq)[/tex]

To obtain the amount of Zn reacted

1 mole of Zn yields 1 mole of ZnCl2

x moles of Zn yields 0.0087 moles of ZnCl2

x = 0.0087 moles of Zn

a) 1 mole of Zn yields 1 mole of H2

0.0087 moles of Zn yields 0.0087 moles of H2

Mass of H2 = 0.0087 moles of H2 * 2 g/mol = 0.0174 grams

b)

Mass of Zn reacted =  0.0087 moles of Zn * 65.38 grams/mole = 0.5688 grams

c)

Percentage of Zn in the alloy = 0.5688 grams/1.203g * 100 = 47.3 %

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Calculate the empirical formula of a compound that has a composition of 5.9% (by mass) hydrogen and 94.1% (by mass) oxygen.​

Answers

Answer:

The empirical formula is the simplest form;

Given:

Oxygen O at 94.1% and

H at 5.9%

Assume 100grams.

94% = 0.941 x 100gm. = 94.1 gm x 1mole/16gm. = 5.88 moles of O

5.9% = 0.059 x 100gm. = 5.9gm. X 1moleH/1.002gm. = 5.88 moles of H

There is one mole of O for each mole of H so the empirical formula is [tex]O_1H_1[/tex]

and written as OH.

Explanation:

[tex]given \: that \: oxygen \: by \: 94.1\% (.941)\\ hydrogen \: by5.9\%(.059) \\ in \: 100gram \: \\ oxygen = 100 g\times .941 = 94.1 \times \frac{1(mol)}{16g} \\ = 5.88moles \: of \: oxygen \\ in \: hydrogen \: = .059\times 100 = 5.9 \times \frac{1mol}{1.002gram} \\ = 5.88mole \: of \: hydrogen \\ \: so \: here \: \: both \: oxygen \: andhydrogen = 5.88 \\their \: ratio = 1 \: 1 \\ so \: emparical \: formula = oh \\ thank \: you[/tex]

What is 3780 cal to kJ

Answers

Answer:

15815.52 kJ

Explanation:

Hope this works for this question

please solve this fast​

Answers

Answer:

b.troposphere

Explanation:

pls mark me brainliest

Round each number to four significant figures
a. 84,791
b. 256.75
C. 431,801
d. 0.00078100

Answers

Answer:

a.

84,791 » 8479

b.

256.75 » 256.8

c.

431,801 » 4318

d.

0.00078100 » 0.0007810

Explanation:

[tex].[/tex]

plss help me :((
The beaker above will measure up to [ ] mL.
What number would be printed on this beaker between 100 and 150? [ ]
What number would be printed on this beaker between 150 and 200? [ ]

Answers

Answer:

250mL, 125mL, 175mL

Explanation:

The beaker has graduated marks every 25mL after the 50mL mark.

Answer:

250ml 125ml 175ml and also do you attend GOC ?

cause same lol

Explanation:

This is a model of a water molecule which has two hydrogen atoms and one oxygen atom. Why ISN'T water considered to be a MIXTURE?
A.
Because the Hydrogen & Oxygen (or O & H) atoms bonded chemically
B.
Because the Hydrogen & Oxygen atoms are easily separated

Answers

A — H2O is one chemically bound molecule, and if you only have one molecule present then it can’t be a mixture, as what is it mixed with??

What is the triangle law of vector quantity​

Answers

Answer:

A law which states that if a body is acted upon by two vectors represented by two sides of a triangle taken in order, the resultant vector is represented by the third side of the triangle.

Explanation:

The atomic number of the element with the maximum number of unpaired 2p electrons in the ground state is

1) 1 2) 7 3) 13 4) 8

Answers

8. As that is the answer. Pls mark me brainliest.

Animation shows a complete revolution of the Earth around the sun. What happens during this time? The moon makes one complete phase change. The moon makes one complete phase change. Four seasons occur on Earth. Four seasons occur on Earth. Earth experiences a complete day. Earth experiences a complete day. Day turns to night.

Answers

Answer:

Four seasons occur on Earth

Explanation:

When the Earth has completely one revolution around the Sun, then it has completed 1 year, and four seasons have occurred in the meantime.

Four seasons occur on Earth when the Earth completes a revolution around the Sun.

The following points can be considered:

The Moon makes one complete phase change when the Moon revolves around the Earth. The Moon makes one complete phase change by a month. Four seasons occur on Earth as a result of the  Earth completes one revolution around the Sun. The  Earth experiences a complete day as a result of the Earth’s rotation along its own axis. The day turns to night as a result of the Earth’s rotation along its own axis.

Therefore the correct answer is Four seasons occur on Earth.

Learn more about Earth:

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What was alchemy?
A. A part of chemistry that experimented only with metals
B. An area of research that investigated all areas of science using
chemistry
C. An early form of chemistry based on experiments and evidence to
test ideas
D. An attempt to turn cheap metals into gold and develop potions using superstitious practices

Answers

Answer:

D

Explanation:

its a very old study and philosophy of how to change basic substances such as metals into other substances

Im not completely sure on this but i think it would be C because it was a thing of the past

What volume of HCl must be used to prepare 350mL of 2.0M HCl solution using a stock solution containing 5L of 12.0M HCl?

Answers

Answer:

~58.3 mL

Explanation:

m1*v1=m2*v2 --> (12.0 M HCL) * v1 = 350mL * 2.0M HCL

--> 350*2.0 = 700

--> 700/12.0 M HCL = 58.3 mL repeating

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