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
hammer [34]
3 years ago
14

I need help on this

Chemistry
1 answer:
sasho [114]3 years ago
3 0

Answer: Y and Z. It's D.

Explanation: W represents evaporation, which is a physical change. X represents dissolving, which is also a physical change. If X and W aren't chemical changes, then Y and Z must be if half of the choices are.

You might be interested in
What does the oxidizing agent do in a redox reaction apex?
densk [106]
Same as balancing a regular chemical reaction! Please see the related question to the bottom of this answer for how to balance a normal chemical reaction. This is for oxidation-reduction, or redox reactions ONLY! These instructions are for how to balance a reduction-oxidation, or redox reaction in aqueous solution, for both acidic and basic solution. Just follow these steps! I will illustrate each step with an example. The example will be the dissolution of copper(II) sulfide in aqueous nitric acid, shown in the following unbalanced reaction: CuS (s) + NO 3 - (aq) ---> Cu 2+ (aq) + SO 4 2- (aq) + NO (g) Step 1: Write two unbalanced half-reactions, one for the species that is being oxidized and its product, and one for the species that is reduced and its product. Here is the unbalanced half-reaction involving CuS: CuS (s) ---> Cu 2+ (aq) + SO 4 2- (aq) And the unbalanced half-reaction for NO 3 - is: NO 3 - (aq) --> NO (g) Step 2: Insert coefficients to make the numbers of atoms of all elements except oxygen and hydrogen equal on the two sides of each half-reaction. In this case, copper, sulfur, and nitrogen are already balanced in the two half-reaction, so this step is already done here. Step 3: Balance oxygen by adding H 2 O to one side of each half-reaction. CuS + 4 H 2 O ---> Cu 2+ + SO 4 2- NO 3 - --> NO + 2 H 2 O Step 4: Balance hydrogen atoms. This is done differently for acidic versus basic solutions. . For acidic solutions: Add H 3 O + to each side of each half-reaction that is "deficient" in hydrogen (the side that has fewer H's) and add an equal amount of H 2 O to the other side. For basic solutions: add H 2 O to the side of the half-reaction that is "deficient" in hydrogen and add an equal amount of OH - to the other side. Note that this step does not disrupt the oxygen balance from Step 3. In the example here, it is in acidic solution, and so we have: CuS + 12 H 2 O ---> Cu 2+ + SO 4 2- + 8 H 3 O + . NO 3 - + 4 H 3 O + --> NO + 6 H 2 O Step 5: Balance charge by inserting e - (electrons) as a reactant or product in each half-reaction. Oxidation: CuS + 12 H 2 O ---> Cu 2+ + SO 4 2- + 8 H 3 O + + 8 e - . Reduction: NO 3 - + 4 H 3 O + + 3 e - --> NO + 6 H 2 O . Step 6: Multiply the two half-reactions by numbers chosen to make the number of electrons given off by the oxidation step equal to the number taken up by the reduction step. Then add the two half-reactions. If done correctly, the electrons should cancel out (equal numbers on the reactant and product sides of the overall reaction). If H 3 O + , H 2 O, or OH - appears on both sides of the final equation, cancel out the duplication also. Here the oxidation half-reaction must be multiplied by 3 (so that 24 electrons are produced) and the reduction half-reaction must by multiplied by 8 (so that the same 24 electrons are consumed). 3 CuS + 36 H 2 O ---> 3 Cu 2+ + 3 SO 4 2- + 24 H 3 O + + 24 e - 8 NO 3 - + 32 H 3 O + + 24 e - ---> 8 NO + 48 H 2 O Adding these two together gives the following equation: 3 CuS + 36 H 2 O + 8 NO 3 - + 8 H 3 O + ---> 3 Cu 2+ + 3 SO 4 2- + 8 NO + 48 H 2 O Step 7: Finally balancing both sides for excess of H 2 O (On each side -36) This gives you the following overall balanced equation at last: 3 CuS (s) + 8 NO 3 - (aq) + 8 H 3 O + (aq) ---> 3 Cu 2+ (aq) + 3 SO 4 2- (aq) + 8 NO (g) + 12 H 2 O (l)


6 0
3 years ago
Read 2 more answers
What is the measure of the efficiency of a chemical reaction? percent yield annual yield actual yield theoretical yield
artcher [175]

Answer:

Precent yield

Explanation:

This is takes into account how much of a substance should have been created (theoretical yield) and compares it to what was actually created (the actual yield).

6 0
3 years ago
What is the name of the process plants use to make the energy (food) they need?
scZoUnD [109]
The answer you looking for is D
8 0
3 years ago
Read 2 more answers
A PNP transistor is connected in a circuit so that the collector-base junction remains reverse biased and the emitter-base junct
maw [93]
Here are the choices:

A. the output current will be much smaller than the input current. 
<span>B. the output voltage will be much larger than the input voltage. </span>
<span>C. the output voltage will be much smaller than the input voltage. </span>
<span>D. the output current will be much larger than the input current
</span>
The correct answer is letter <span>B. the output voltage will be much larger than the input voltage.</span>
5 0
3 years ago
If one iron nail weighs 2.0 grams, what would be the mass of 6.022 x 10^23 nails?
Maru [420]

Answer:

1.2x10^{24}g

Explanation:

Hello!

In this case, it is possible to treat this problem by using a proportional factor which indicates one iron nail equals 2.0 grams:

\frac{2.00g}{1nail}

Now, for an amount of 6.022x10²³ nails, the corresponding mass will be:

6.022x10^{23}nail*\frac{2.00g}{1nail} \\\\1.2x10^{24}g

Best regards!

8 0
2 years ago
Other questions:
  • What type of orbital overlap is responsible for the π bond between carbon and oxygen in the molecule below?
    7·1 answer
  • 3Cu(s) + 8HNO3(aq) → 3Cu(NO3)2(s) + 2NO(g) + 4H2O(l)
    14·1 answer
  • What is the formula and formula mass of potassium sulphate?
    15·2 answers
  • A chef is testing out a new set of iron cookware. He knows that iron has a specific heat of 445 J/kg°C. He heats a 2 kg iron ski
    5·1 answer
  • The student placed 10 mL of PbCl2 (saturated solution) in the test tube and added a pinch of NaCl. A white precipitate of PbCl2
    5·1 answer
  • A b or c<br><br> hurry please!!
    10·2 answers
  • The stimulus is related to?​
    10·1 answer
  • How many times more acidic is pH2 than pH4?
    10·1 answer
  • How many Neutrons are in the Nucleus of an atom with an atomic number of 25? (Use Periodic Table for mass.)
    9·2 answers
  • A gem has a mass of 5. 50 g. When the gem is placed in a graduated cylinder containing 9. 500 ml of water, the water level rises
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!