Which of the following is a pure substance?
Chlorine B. salt solution C. bronze D. salad dressing

What is the boiling point of pure water?
About 1000 C B. exactly 1000 C C. it varies D. slightly above 1000 C

Which is an example of a chemical change?
Water evaporating B. butter melting C. match burning D. powder being made

Which of these indicate a chemical change?
Color change B. temperature change C. gas-forming D. all of the above

Which of these is an impure substance?
Tap water B. gold C. carbon dioxide D. boron

Answers

Answer 1

Answer:

1. B

2. 100 C

3.  C

4. D

5. D

Explanation:


Related Questions

Convection currents in Earth's core transfer heat and material to the surface.

True or False?

Answers

Answer: False

Explanation: The plate tectonics  move due to convection currents of the mantle; the cooler upper mantle descends while the hotter lower mantles ascend. The heat that drives these convection currents emanated from the core of the earth (not the sun).

How many moles are in 5.30 X 1023 molecules of H2O?

Answers

Answer:

0.880 (0.88039867109 to be exact)

Explanation:

To convert from molecules to moles, simply divide by Avogadro's number which is 6.02 x 10^23

So, 5.30x10^23/6.02x10^23 = 0.880

When the equation H2 + Fe3O4 = Fe + H2O is completely balanced using the smallest whole numbers, the coefficient oH2 would be A.) 1 B.)2 C.) 3 D.) 4

Answers

Answer:

H2 would have a coefficient of 2.

Explanation:

According to the balanced chemical equation, the coefficient of hydrogen is 4.

What is chemical equation?

Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.

A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .

The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.

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28g of aluminum reacts with 45g oxygen

1) complete balanced equation?
2) what is the limiting reactant?
3) how many grams of product could be formed?
4) how many grams of excess would you predict?
5) if you actually measured 50g of product, what is the percent yield?

Answers

Answer:

answer below:

Explanation:

1) 4 Al + 3 O2 --> 2Al2O3.

2) Al mol= 28/27 = 1.037mol

O mol= 45/16 = 2.812mol

Al : O

4 : 2

x : 2.812

cross multiply

4 x 2.812/2  = 5.624 mol of Al

Al is limiting reactant

3) 28/5.246 = 5.34product can be formed (not that much sure)

4) 45/ 0.5185 = 86.79

86.79 - 5.34 = 81.45g

5) 50 / 81.45 x 100 = 61.39% ( i guess)

i hope this hleps you

Name this alkane.

A five-sided polygon with one point facing left. A straight line extends from that point, then a line slanting up to the left, then another straight line extends left.
propylcyclopentane
pentylpropane
nonacyclotane
phenylcyclopentane

Answers

Answer:

propylcyclopentane

Explanation:

The rest Are swiggly lines and more than 5 sides

The organic compounds which consist of single bonded carbon and hydrogen atoms are called alkanes. They are also called the saturated hydrocarbons. Here the given alkane is propylcyclopentane. The correct option is A.

What is propylcyclopentane?

The propylcyclopentane is an alkane which is the simplest family of hydrocarbons. It is a cyclic hydrocarbon which acts as the major component of gasoline and it is also used in the manufacture of synthetic resins and rubber adhesives.

The propylcyclopentane is an important cycloalkane which contains five carbon atoms bonded to two hydrogen atoms above and below the plane. It appears as a clear colourless liquid with a petroleum like odor. It is less dense than water and it is insoluble in water.

Propylcyclopentane is a member of cyclopentanes, a cycloalkane and a volatile organic compound. Its molecular formula is C₈H₁₆. It can also be called as 1 - Cyclopentylpropane.

Thus the correct option is A.

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Giving brainliest! Please help pleaseeee

Answers

Answer:

Id want to know how the nucleus looks like upclose, is it really that neutrons and protons are bond together, or are they just sticking in together. I'd also wanna look at electrons, or even possible hold them so that i can see the mass it really has

Explanation:

Calculate the approximate initial boiling point (in oC) of a solution of 285 g of

magnesium chloride in 2.0 kg of water. The kb of water is (0.52°C/m)

Answers

Answer:

do u take links bcs I can give u one with the answer?

The approximate initial boiling point of Magnesium chloride solution has been 102.33 degree Celsius.

The pure water has boiling point 100 degree Celsius. With the addition of the solvent, the boiling point has been increased. The change in the boiling point ([tex]\Delta T_b[/tex]) has been given as:

[tex]\Delta T_b=i.K_b.b[/tex]

Where, i has been the van't Hoff factor

[tex]K_b[/tex] has been the ebullioscopic constant

b has been the molality of the sample

The dissolution of magnesium chloride in water has been given as:

[tex]\rm MgCl_2\;(aq)\;\rightarrow\;Mg^2^+\;+\;2\;Cl^-[/tex]

The i has been the amount of molecules that has been formed by the dissociation of 1 molecule. The dissociation of Magnesium chloride has been resulted in the 1 Mg and 2 Cl. Thus, the i for Magnesium chloride has been 3.

The molality (m) of the solution has been given as:

[tex]m = \dfrac{m_s_o_l_u_t_e}{mwt}\;\times\;\dfrac{1000}{m_s_o_l_v_e_n_t}[/tex]

Where, [tex]m_s_o_l_u_t_e=285\;\text {g}\\m_s_o_l_v_e_n_t=2\;\text{kg}\\mwt=95.211\;\text{g/mol}[/tex]

Substituting the values, molality of the Magnesium chloride solution (b) can be given as:

[tex]b=\dfrac{285}{95.211}\;\times\;\dfrac{1}{2}\;\text{m}\\b=1.49\;\text{m}[/tex]

The molality of the solution has been 1.49 m.

Substituting the values for change in temperature:

[tex]\Delta T_b=3\;\times\;0.52\;\times\;1.49\;^\circ \text C\\\Delta T_b=2.33\;^\circ \text C[/tex]

The rise in boiling temperature with the addition of 285 g of Magnesium chloride has been 2.33 [tex]\rm ^\circ C[/tex]. Since, the initial temperature for pure solvent has been 100 degree Celsius.

The initial temperature of Magnesium chloride solution has been the sum of two. Thus:

[tex]\text {Initial temperature}=100^\circ \text C\;+\;2.33\;^\circ \text C\\\rm Initial\;temperature=102.33\;^\circ C[/tex]

The initial temperature of magnesium chloride solution has been 102.33 degree Celsius.

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7. Where do amino acids reside ?

Answers

Answer:

Explanation:

Polar side chains tend to be present on the surface of a protein where they can interact with the aqueous environment found in cells. On the other hand, non-polar amino acids tend to reside within the center of the protein where they can interact with similar non-polar neighbors.

1N2 + 3H2 -->

2NH3

When 23.15 g of N, and 36.85 g of H2 react, what is the maximum amount of NH3 that can be produced?

Answers

Answer:

28.23 g NH₃

Explanation:

The balanced chemical equation is:

N₂(g) + 3 H₂(g) → 2 NH₃(g)

Thus, 1 mol of N₂ reacts with 2 moles of H₂ to produce 2 moles of NH₃. We convert the moles to mass (in grams) by using the molecular weight (MW) of each compound:

MW(N₂) = 2 x 14 g/mol = 28 g/mol

mass N₂= 1 mol x 28 g/mol = 28 g

MW(H₂) = 2 x 1 g/mol = 2 g/mol

mass H₂ = 3 mol x 2 g/mol = 6 g

MW(NH₃) = 14 g/mol + (3 x 1 g/mol) = 17 g/mol

mass NH₃= 2 moles x 17 g/mol = 34 g

Now, we have to figure out which is the limiting reactant. For this, we know that the stoichiometric ratio is 28 g N₂/6 g H₂. If we have 36.85 g of H₂, we need the following mass of N₂:

36.85 g H₂ x 28 g N₂/6 g H₂ = 171.97 g N₂

We have 23.15 g N₂ and we need 171.97 g. So, we have lesser N₂ than we need. Thus, the limiting reactant is N₂.

Now, we calculate the product (NH₃) by using the stoichiometric ratio 34 g NH₃/28 g N₂, with the mass of N₂ we have:

23.25 g N₂ x 34 g NH₃/28 g N₂ = 28.23 g NH₃

Therefore, the maximum amount of NH₃ that can be produced is 28.23 grams.

If 45 grams of NaNO3 is dissolved in 100 grams of water at 40 C, how much more is needed to have a saturated solution?

Answers

Answer:

I literally have no idea

in which of the following is number of neutrons correctly represented?​

Answers

Answer:

²³⁸₉₂U has 146 neutrons

Explanation:

To know which option is correct, we shall determine the number of neutrons in each case. This can be obtained as follow:

For ²⁴₁₂Mg:

Mass number (A) = 24

Proton number (P) = 12

Neutron number (N) =?

A = P + N

24 = 12 + N

Collect like terms

N = 24 – 12

N = 12

Thus, there are 12 neutrons in ²⁴₁₂Mg

For ⁷⁵₃₃As:

Mass number (A) = 75

Proton number (P) = 33

Neutron number (N) =?

A = P + N

75 = 33 + N

Collect like terms

N = 75 – 33

N = 42

Thus, there are 42 neutrons in ⁷⁵₃₃As

For ¹⁹₉F:

Mass number (A) = 19

Proton number (P) = 9

Neutron number (N) =?

A = P + N

19 = 9 + N

Collect like terms

N = 19 – 9

N = 10

Thus, there are 10 neutrons in ¹⁹₉F.

For ²³⁸₉₂U:

Mass number (A) = 238

Proton number (P) = 92

Neutron number (N) =?

A = P + N

238 = 92 + N

Collect like terms

N = 238 – 92

N = 146

Thus, there are 146 neutrons in ²³⁸₉₂U

Considering the options and the illustration made above, Only ²³⁸₉₂U has the correct number of neutrons written along side.

3 Module 1 - Lessons
Dashboard
Ready
C levertal
Infinite can
& 2nd
the amount of mass in a given space

Answers

Jdbshx s. Hs xj. Si. So uxbsiak. C

What statements are true about mutations to DNA?

Answers

Answer:

Is this a general question or is there supposed to be a picture

Explanation:

what is gold on the periodic table of element

Answers

Answer:

Gold is element 79 and its symbol is Au.

The answer is Gold is Au

The partial pressures of CH4, N2, and O2 in a sample of gas were found to be 248 mm Hg, 707 mm Hg, and 518 mm Hg, respectively. What is the mole fraction of Nitrogen gas?

Answers

total pressure=248+707+518=1473mmHg

partial pressure=total pressure×mole fraction

mole fraction of N2

=partial pressure of N2/total pressure

=707mmHg/1473mmHg

=0.4800

At which position on the diagram would an apple have the greatest potential energy?

Answers

Answer:

Position 1 because it is the highest from the ground.

Hope this helps!

what is the molecular shape of N2O2?

Answers

Answer:

If you're just looking at the Lewis Structure from the perspective of the octet rule, it does appear that the structure is correct. Dinitrogen always has a lone pair of electrons which could conceivably be used for dative bonding as you suggest. So from that perspective there appears to be nothing wrong at all - other than that it doesn't exist in nature in this way.

Explanation:

what is the formula of the compounds in B

pls help

Answers

Answer:

PCl3

Explanation:

The molecular formular of a compound shows the exact number of atoms of elements present in the compound. In this illustration, there is one atom of P and 3 atoms of Cl.

The formular is given as; PCl3

Answer:

PCl³

Explanation:

because there are 1 phosphorus atom and 2 chlorine atom.

What is the correct IUPAC name for the acid: H2Lv

Answers

Hydrogen chalcogenides

A 5.00 L flask contains 7.94 g of a gas at STP. What is the molar mass of the gas?​

Answers

Answer: 35.6 g/mol

Explanation: I guessed and got it correct

The molar volume of any gas behaving ideally at STP is 22.414 L. The molar mass of the gas at STP is 35.59 g.

What is molar mass?

The molar mass of a substance is defined as the mass of one mole of molecules. In other words one gram molecular mass of a substance is same to its molar mass in g mol⁻¹.

The molar mass of a substance can be obtained by adding the atomic masses of each elements.  At 0°C and 1 atm, 1 mole of any gas behaving ideally occupies a volume of 22.414 L.

Here 5.00 L of the gas at STP has a mass of 7.94. Then the molar mass of 22.414 liters of the gas can be calculated as:

7.94 × 22.414/5.00 = 35.59 g.

Thus the molar mass of the gas is 35.59 g.

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An organism from the past that is related to all the organisms in the group is called?​

Answers

Answer:

phylogenic trees/phylogeny

Explanation:

the evolutionary history and relationship of an organism or group of organisms is called its phylogeny

PLEASE HELP!
1) What type of reaction is this?
Zn + 2HCl -----> ZnCl + H
2) Balance the equation (Hint, you need to balance the left side with the right side)

Answers

1) single replacement

2) Zn + 2HCl -----> ZnCl + H

equation is already balanced

true or false : Color Changes are used to show reaction completion

Answers

Answer:

True

Explanation:

It means the reaction is occuring.

how does pentene become pentane?
How does propene become propane?​

Answers

Pentane is derived from the petroleum raw materials, natural gas and crude oil. It is generally marketed in a compressed liquefied form at 99% purity.

4. For water, H20 represents
only the empirical formula
only the molecular formula
only the structural formula
both the empirical & molecular formulas

Answers

Answer:

The empirical and molecular formula because the ratio is 2:1 and there is 2 hydrogen atoms and 1 oxygen atom.

Hope this helps!


What causes dipole interactions?

bonding of a covalently bonded hydrogen to an unshared electron pair

attraction between ions

attraction between polar molecules

sharing of electron pairs

Answers

Attraction between polar molecules

What is the difference between a pure solvent and a solution? Do they have the same physical properties?

Answers

Answer:

The physical properties of a solution are different from those of the pure solvent. ... Colligative properties are those physical properties of solutions of nonvolatile solutes that depend only on the number of particles present in a given amount of solution, not on the nature of those particles.

Pure solvent v/s Solution:A solution is a homogeneous mixture consisting of a solute dissolved into a solvent while the solvent is the dissolving medium.The physical properties for both differs. Colligative properties are those physical properties of solutions of nonvolatile solutes that depend only on the number of particles present in a given amount of solution, not on the nature of those particles.Pure solvents have only one component like n-hexane, water while a solution is a mixture of solute and solvent for example: salt solution.The boiling point of the solvent in a solution is higher than that of the pure solvent.

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You have 54.32 grams of PbCl4. How many moles of PbCl4 do you have?
If you show the work that would be great!

Answers

Answer is 0.1565417867........

The maximum water vapor that air can hold at 30°C is about 30 grams/cubic meter. If the humidity of the air is currently 6 grams/cubic meter at the same temperature, the relative humidity is

Answers

The answer is 16 due to the 30 grams cubic meter and the humidity has to be added
the answer is 16 due to 30 grams of cubic

what do you need to know

Answers

Can you reword the question? I don’t understand what you are trying to say.
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