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
Alenkasestr [34]
3 years ago
6

Write the ΔH system for each of the following changes in physical state

Chemistry
1 answer:
8_murik_8 [283]3 years ago
4 0

Answer:

a. positive

b. negative

c. positive

d. negative

Explanation:

In a exothermic reaction, heat is written as a product (del H is negative), whereas in an endothermic reaction heat is written on the reaction side (del H is positive).

For a, it is endothermic process. We know this because to go from solid to liquid you need to put energy into the system. When we put energy into a chemical system it is said to be an endothermic reaction.

For b, it is exothermic reaction. This is because you have to lose the extra energy to go from less ordered states (gas) to more ordered state (liquid). Gas is less ordered because its molecules are freely moving and such. Another way of thinking about this question is just putting the heat on product side and think if I was going in reverse direction I would put heat in product because I would need to add heat to liquid to turn to gas (and if heat is added to product side we know its exothermic). Two ways of thinking whichever you prefer.

The rest have similar explaination.

You might be interested in
27.2g CuCl2 was dissolved in 2.50 L of the water. What is the molality of the solution?
stealth61 [152]

5.167g of calcium chloride is dissolved in 101.0mL of water in a calorimeter whose calorimeter constant is 15.3J/°C. The temperature rises from 18.4°C to 27.2 ...

5 0
2 years ago
2. Lysosomes operate within the cell bye to the
Marat540 [252]

Answer:

C

Explanation:

Lysosomes contain digestive enzymes which are used for digestion of food and dead organelles. It fuses with a vacuole which contain the targeted material(food or dead organelles) and digests the material inside it

3 0
3 years ago
Iron (III) oxide reacts with solid carbon in the followed reaction: 2Fe2O3(s) + 3C(s) → 4Fe(s) + 3CO2(g) What mass of Fe2O3 is n
Veseljchak [2.6K]

953.6 g of iron (III) oxide (Fe₂O₃)

Explanation:

We have the following chemical reaction:

2 Fe₂O₃ (s) + 3 C (s) → 4 Fe (s) + 3 CO₂ (g)

We calculate the number of moles of CO₂ by using the following formula:

pressure × volume = number of moles × gas constant × temperature

number of moles = (pressure × volume) / (gas constant × temperature)

number of moles of CO₂ = (2.1 × 100) / (0.082 × 300)

number of moles of CO₂ = 8.54 moles

Taking in account the chemical reaction we devise the following reasoning:

if         2 mole of Fe₂O₃ produces 3 mole of CO₂

then   X moles of Fe₂O₃ produces 8.54 mole of CO₂

X = (2 × 8.54) / 3 = 5.69 moles of Fe₂O₃

number of moles = mass / molar weight

mass =  number of moles × molar weight

mass of Fe₂O₃ = 5.69 × 160 = 953.6 g

Learn more about:

number of moles

brainly.com/question/14111505

#learnwithBrainly

6 0
2 years ago
Read 2 more answers
4 examples of Substances that sublime?
AVprozaik [17]

1. Dry Ice (solid carbon dioxide)

2. Iodine

3. Arsenic

4. Naphthalene

3 0
3 years ago
How to do an equation
pav-90 [236]
What do you mean by that Oh wait do you mean like 2×2=4 or 2+2=4 something like that maby?? I am still confused?? XD
7 0
3 years ago
Other questions:
  • Should a mortar and pestle should be used for grinding only one substance at a time
    11·1 answer
  • Now consider the example of a positive charge q moving in the xy plane with velocity v⃗ =vcos(θ)i^+vsin(θ)j^ (i.e., with magnitu
    10·1 answer
  • Gaseous methane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water. Suppose 0.802 g of methane i
    5·1 answer
  • What is an endothermic reaction?
    13·1 answer
  • Calculate the amount of heat energy, in kJ, needed to increase the temperature of 200g of water by 300 C.
    15·1 answer
  • Word equation for Silver being added to sulphuric acid
    7·1 answer
  • Please Help!!!!!!!!!!!!!!
    13·2 answers
  • PLEASE HELP ME!!!! I DON'T UNDERSTAND
    12·1 answer
  • Heat transfer that occurs within or between solid objects is called
    12·2 answers
  • Need help ASAP <br> Ahsb
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!