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zavuch27 [327]
3 years ago
8

16.H2O (water) and NaCl (salt) are _________ that are in salt water, which is a(n) __________. Water and salt contain the ______

______ hydrogen, oxygen, sodium, and chlorine.
Compounds; mixture; elements
Mixture; compounds; elements
Element; compounds; mixture
Compound; elements; compounds

12.The number of _____ determines which element it is.

electrons
protons
positrons
neutrons
Chemistry
1 answer:
trapecia [35]3 years ago
4 0
#1...<span>Mixture; compounds; elements
#2...Protons 

</span>
You might be interested in
1. Holding 100mL of water (ebkare)________________2. Measuring 27 mL of liquid(daudgtear ldnreiyc)________________3. Measuring e
Andreas93 [3]

Answer: The correct matching are as follows:

1. BAKER: Holding 100mL of water.

Beaker is mainly used for holding liquids in the laboratory, but it can be used for a variety of other purposes such as measuring liquids or as a collecting vessel in acid-base titration. It comes in different sizes and it can be made of glass or plastic.

2. GRADUATED CYLINDER: Measuring 27mL of liquid

Graduated cylinder is primarily used in the laboratory to accurately measure specific volume of liquid. It's degree of accuracy is moderate. Volumentric glass is more accurate than graduated cylinder and it is used when high degree of accuracy is needed.

3. BURRET: Measuring exactly 43mL of an acid.

Biuret is a long glass tube with calibration and with a tap at its end. It is usually used during acid base titration. During titration, a known quantity of acid is pour into the burrete and then added gradually to the base.

4. BALANCE: Massing out 120 g of sodium chloride.

Balance is a common laboratory tool. It is used to measure the mass of solid substances. Balance comes in different sizes and shapes. For instance, chemical balance is used in the laboratory to measure out specific amount of solid or powdered chemicals.  

5. WIRE GAUZE: Suspending glassware over the Bunsen burner.  

Wire gauze is usually used in the laboratory in order to prevent direct heating of chemical compounds. The wire is typically placed first on the busen burner and then the substance to be heated will be placed on the wire.

6. FUNNEL: Used to pour liquids into containers with small openings or to hold filter paper.

Funnel is used for variety of purpose in the laboratory; it can be used to ease pouring of liquids and it can also be used during separation process, for instance during filtration. It can be made of glass or plastic.

7. WELL PLATE: Mixing a small amount of chemicals together.  

Well plate refers to a laboratory ware that is flatly shaped like a big tray and it contains many holes called 'wells'. The wells serve to hold small amount of chemicals. Well plate is typically used for sample collection and chemical preparation.

8. TEST TUBE CLAMPS: Heating contents in a test tube.

Test tube clamps are typically used to hold test tubes when one want to apply heat to the test tubes contents. The clamps are usually made of wood, which is a poor conductor of heat. This allow the users to hold the clamp conveniently during heating.

9.  TEST TUBE RACK: Holding many test tubes filled with chemicals.

Test tube rack is used in the laboratory to hold large number of test tubes that contain chemicals. This makes it easy for one to transport the test tubes. Test tube rack are usually made of plastic or wood.

10.    WIRE BRUSH: Used to clean the inside of test tubes or graduated cylinders.

Wire brush is used to clean the inside of narrow glass wares such as test tubes and cylinder. The wire brush facilitate proper cleaning of the inside of the glasses.

11. WATCH GLASS: Keeping liquid contents in a beaker from splattering.

Watch glass is a circular piece of glass that can be used for different purposes in the laboratory. it can be used to prevent splattering of liquid chemicals. It can also be used as a surface for liquid evaporation.

12. ERIENMEYER FLASK: A narrow-mouthed container used to transport, heat or store substances, often used when a stopper is required.

Erienmeyer flask is a multipurpose glassware with a flat bottom and a narrow neck that can hold stopper. It is used for different purposes such as storage of solution and transportation of liquid chemicals.

13. BUSEN BURNER: Heating contents in the lab.

Busen burner is used in the laboratory to produce heat, It is usually connected to a cylinder of gas fuel. Chemical can be heated either directly on indirectly on the bursen burner. Wire gauze is usually used when direct heating is not desired.

14. TONGS: Transport a hot beaker.

Tongs are used to hold hot beakers and to move them from one point to another. It is not safe to use bare hands to carry heated chemicals in the lab, tongs should always be used to hold beakers over busen burner and also to transport them.

15. GOOGLES: Protects the eyes from flying objects or chemical splashes.

Googles are usually worn in the laboratory in order to protect one's eyes from accidental chemical splashes. They come in variety of size and shapes and are usually made of rubber. The thickness of the lenses vary and googles with thick lenses should be worn when one is working dangerous liquid chemicals.

16. MOTAR AND PESTLE: Used to grind chemicals to powder.

Mortal and pestle come together; they are used to grind solid chemical into powder. This usually occur when one want to increase the surface area of a solid substance in order to speed up the rate of chemical reaction. Mortal and pestle are usually made of ceramic.

6 0
2 years ago
A 2.684-g sample of zinc oxide was reduced by hydrogen gas, resulting in 2. 156 g of pure zinc metal. Determine the empirical fo
Afina-wow [57]

The empirical formula of the initial zinc oxide is ZnO.

<h3>What is Empirical Formula?</h3>

The empirical formula of a compound represents the ratios of elements in a compound but not the actual numbers or arrangement of the atoms.

It is the lowest whole number ratio of the element in the compound.

<h3>How to find out the empirical formula?</h3>
  • Find out the given masses and molar masses of the elements

The molar mass of Zn = 65 gmol⁻¹

Given the mass of Zn = 2.156 g

The molar mass of Oxygen = 16 gmol⁻¹

The mass of Oxygen = Mass of a sample of zinc oxide - the mass of zinc metal

                                   = (2.684 - 2.156) g

                                   = 0.528 g

  • Find the number of moles of the elements in the compound

The number of moles is given by

n = \frac{m}{M}

where m = given mass and

M = Molar mass

Number of moles of Zinc = \frac{2.156}{65} = 0.033 moles

Number of moles of Oxygen =\frac{0.528}{16} = 0.033 moles

  • Find the simplest ratios of the elements in the compound. To find the ratios simply divide the number of moles by the lowest number of moles obtained.

Here, the number of moles is the same for both elements. Hence, the simplest ratio for Zn:O is 1:1.

Therefore, the empirical formula of zinc oxide is ZnO.

Learn more about the empirical formula:

brainly.com/question/1603500

#SPJ4

 

5 0
1 year ago
What change results in the formation of different substances
scoundrel [369]
The amount of molecules assembled, the processes performed on the substances. I'm not exactly sure of the question to be honest, but there's a start
7 0
3 years ago
What are subatomic particles?​
vova2212 [387]

Explanation:

a particle smaller than an atom (e.g., a neutron) or a cluster of such particles (e.g., an alpha particle).

6 0
2 years ago
How many moles does the mass quantity 130g of H2O have?
SVETLANKA909090 [29]
It has 7.22 moles.... mole =mass/molar mass
molar mass of H2O=18
130/18=mole
7 0
3 years ago
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