All categories

3 years ago

Which of the following results in a chemical change in matter?

Chemistry

1 answer:

kodGreya [7K]3 years ago

7 0

You have a raw egg you put it in a hot pan boom cooked egg most chemical changes are nonreversibal <span />

You might be interested in

(Direct answer=Upvote cause I aint smart xD)

Vedmedyk [2.9K]

Paper is shredded, the paper is physically being shredded, iron rusting is due to oxygen reacting with it, gas is burned releases and odor which is a sign of chemical, shirt being bleached is chemical reaction.

5 0

3 years ago

When 2 moles of Fe(s) react with Cl2(g) to form FeCl3(s) according to the following equation, 799 kJ of energy are evolved.

GenaCL600 [577]

Answer:

1. Exothermic.

2. -1598 kJ.

Explanation:

Hello!

1. In this case, according to the reaction, we can infer that 799 kJ of energy are evolved (given off, released) it means that the enthalpy of reaction is negative as the reactants have more energy than the products; which means this is an exothermic reaction.

2. Here, as we know that the enthalpy of reaction is -799 kJ/mol, we can compute the q-value as shown below, considering the reacted 2 moles of solid iron:

$q=2mol*-799 kJ/mol\\\\q=-1598kJ$

Which means that 1598 kJ of energy are evolved when 2 moles of solid iron react.

Best regards!

4 0

3 years ago

Complete the following single replacement reaction. If they don’t react, just write “NR”

Kipish [7]

Here we have to complete the given single replacement reactions.

The replacement reactions are-

1) Fe (s) + CuCl₂ (aq) → FeCl₂ (aq) + Cu (s)

2) Cu (s) + FeCl₂ (aq) → NA

3) K (s) + NiBr₂ (aq) → NA

4) Ni (s) + KBr (aq) → NiBr₂ (aq) + K (s)

5) Zn (s) + Ca(NO₃)₂ (aq) → Zn(NO₃)₂ (aq) + Ca (s)

6) Ca (s) + Zn(NO₃)₂ (aq) → NA

The replacement reactions can be explained in light of the redox potential.

The standard reduction potential of the half cells involved in these reactions are:

Fe²⁺ + 2e → Fe (E° = -0.441V); Cu²⁺ + 2e → Cu (E° = 0.674V)

Ni²⁺ + 2e → Ni (E° = -0.23V); Zn²⁺ + 2e → Zn (E° = -0.763V)

We know the half cell reactions in which the standard reduction potentials are positive are allowed.

1) The reaction is possible as Cu²⁺/Cu and Fe/Fe²⁺ standard reduction potentials are positive.

2) The reaction is not possible as Cu/Cu²⁺ and Fe²⁺/Fe standard reduction potentials are negative.

3) The reaction is not possible as Ni²⁺/Ni standard reduction potential is negative.

4) The reaction is possible as Ni/Ni²⁺ standard reduction potential is positive.

5) The reaction is possible as Zn/Zn²⁺ standard reduction potential is positive.

6) The reaction is possible as Zn²⁺/Zn standard reduction potential is negative.

4 0

3 years ago

Mapping the ocean floor did not provide any new evidence for the theory of continental drift.

777dan777 [17]

False. ......................................

6 0

3 years ago

Read 2 more answers

Cheryl kept a potted plant near a window. After two days, she observed that the plant had drooped as shown.

Alex_Xolod [135]

A watering the plant. Plants wilt or droop when there’s not enough water because it helps reduce the amount of a surface area

3 0

3 years ago