1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Softa [21]
3 years ago
6

Which combinations of substances resulted in a chemical change?

Chemistry
1 answer:
NeX [460]3 years ago
8 0
Any chemical reaction would always result to a chemical change. If you can see observations of a change in color, bubbling or any liberation of gas, formation of a precipitate, or a change in temperature, then a chemical change has occurred. I can't say which combinations would result to a chemical change because there are no choices. I can only give an example. If HCl reacts with NaOH,

HCl + NaOH → NaCl + H₂O

This is a chemical change because a precipitate in the form of NaCl salt is formed.
You might be interested in
Fix the formula for Mg3F<br> Write out the full correct formula?
LenKa [72]

Answer:

MgF_2

Explanation:

Hello!

In this case, since, when we see an ionic binary salt like that formed by magnesium (metal) and fluorine (nonmetal), in order to set up the correct molecular formula we need to check out the periodic table in order to identify the suitable oxidation states, since metals remain positively charged as they lose electrons and nonmetals negatively charged as they gain electrons.

In such a way, since the oxidation state of magnesium is +2 and that of fluorine is -1 we write:

Mg^{2+}F^-

Next, we need to exchange the oxidation states as subscripts without the charge to obtain:

MgF_2

Which is the corrected molecular formula for magnesium fluoride.

Best regards!

3 0
3 years ago
1 If it takes 67 mL of 0.15 M NaOH to neutralize 134 mL of an HCl solution, what is the concentration of the HCl? (5 points)
Neporo4naja [7]

Answer:

Q₁-  The concentration of HCl = 0.075 N = 0.075 M.

Q₂-  The concentration of KOH = 7.675 mN = 7.675 mM.

Q₃-  The concentration of H₂SO₄ = 0.2115 N = 0.105 M.

Q₄-  The equivalence point is the point at which the added titrant is chemically equivalent completely to the analyte in the sample whereas the endpoint is the point where the indicator changes its color.

Explanation:

<u><em>Q₁: </em></u>

  • As acid neutralizes the base, the no. of gram equivalent of the acid is equal to that of the base.
  • The normality of the NaOH and HCl = Their molarity.

∵ (NV)NaOH = (NV)HCl

∴ N of HCl = (NV)NaOH / (V)HCl = (0.15 N)(67 mL) / (134 mL) = 0.075 N.

∴ The concentration of HCl = 0.075 N = 0.075 M.

<em><u>Q₂:</u></em>

  • As mentioned in Q1, the no. of gram equivalent of the acid is equal to that of the base at neutralization.
  • The normality of H₂SO₄ = Molarity of H₂SO₄ x 2 = 0.050 M x 2 = 0.1 N.

∵  (NV)H₂SO₄ = (NV)KOH

∴ N of KOH = (NV)H₂SO₄ / (V)KOH = (0.1 N)(27.4 mL) / (357 mL) = 7.675 x 10⁻³ N = 7.675 mN.

∴ The concentration of KOH = 7.675 mN = 7.675 mM.

<em><u>Q₃:</u></em>

  • As mentioned in Q1 and 2, the no. of gram equivalent of the acid is equal to that of the base at neutralization.
  • The normality of NaOH = Molarity of NaOH = 0.5 N.

∵ (NV)H₂SO₄ = (NV)NaOH

∴ N of H₂SO₄ = (NV)NaOH / (V)H₂SO₄ = (0.5 N)(55 mL) / (130 mL) = 0.2115 N.

∴ The concentration of H₂SO₄ = 0.2115 N = 0.105 M.

<em><u>Q₄:</u></em>

  • The equivalence point is the point at which the added titrant is chemically equivalent completely to the analyte in the sample whereas the endpoint is the point where the indicator changes its color.
  • The equivalence point in a titration is the point at which the added titrant is chemically equivalent completely to the analyte in the sample. It comes before the end point. At the equivalence point, the millimoles of acid are chemically equivalent to the millimoles of base.
  • End point is the point where the indicator changes its color. It is the point of completion of the reaction between two solutions.
  • The effectiveness of the titration is measure by the close matching between equivalent point and the end point. pH of the indicator should match the pH at the equivalence to get the same equivalent point as the end point.
4 0
3 years ago
A distance force is a force that acts on an object but
Mumz [18]
I believe the answer is C. Does not touch it

Someone please correct me if I am wrong.
7 0
4 years ago
Read 2 more answers
What is the difference between an enthalpy driven reaction and entropy driven reaction?
Crazy boy [7]
<span>Enthalpy is regarding the amount of heat that is given off or taken in during the process of a reaction, while entropy is about the disorderliness of a reaction. 
Both are related in the equation ∆G=∆H-T∆S, where ∆G is the Gibbs free energy. So we can say that a reaction is both enthalpy and entropy driven. It's like, both of them are interlinked with each other. </span>
5 0
4 years ago
Determine the mass in grams of each of the following:
nekit [7.7K]
We know, Given mass = Molar mass * Number of moles.

A.) <span>1.25 mol CaF</span>₂

Number of moles = 1.25
Molar mass = 78

So, Mass = 78 * 1.25 = 97.5 g

B.) 3.4 mol (NH₄)₂SO₄

Number of moles = 3.4
Molar mass = 132

Mass = 3.4 * 132 = 448.8 g

Hope this helps!
3 0
3 years ago
Other questions:
  • answer the following question by entering the numeric value with appropriate units. if the length of one side of a square is 12.
    9·1 answer
  • What happens to two substances when they dissolve?
    7·1 answer
  • What happens when you open a bottle of perfume?
    8·1 answer
  • When balancing an equation, should you adjust the subscripts or the coefficients?
    15·2 answers
  • 30. The of an object is different on every<br> planet in the solar system.
    11·1 answer
  • Lavoisier made a list of thirty-three elements. His list of elements challenged the age-old idea that
    14·2 answers
  • When copper metal is added to nitric acid, the following reaction takes place
    9·1 answer
  • Which of the following is notan example of a science?
    11·1 answer
  • Which of the following is pure compound?<br> Ethanol,petrol,steel ,tapwater
    10·2 answers
  • Why do you think there are many wind systems between a pole and the equator instead of just one large single wind system
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!