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
kipiarov [429]
3 years ago
15

Which process is endothermic?a)b)c)d)The evaporation of water from the skin.The burning of candle wax.The oxidation of iron in a

chemical hand warmer.The combustion of natural gas in a stove
Chemistry
1 answer:
BlackZzzverrR [31]3 years ago
6 0

Answer:

The answer is option a. The evaporation of water from the skin

Explanation:

An endothermic reaction is any synthetic reaction that retains heat from its environment. The ingested energy gives the enactment energy to the reaction to happen.

No new bonds formed, no bonds broken in this example. water molecules go from liquid to vapour (gas ), intermolecular bond exist between polar (-OH) molecules and energy is required to break these bonds during the change from liquid to gas. So, it is endothermic .

Remaining three above examples are exothermic. combustion of gas releases energy(exothermic). burninig of the candle exothermic because the energy released from the oxygen into carbon dioxide and water.oxidation of iron also exothermic

You might be interested in
Is salt water solution a homogeneous mixture
GuDViN [60]

Answer:

yes, it is a homogeneous mixture because the different parts cannot be seen.

Explanation:

8 0
3 years ago
Read 2 more answers
What is the ph of a solution made by mixing 25.00 ml of 0.100 m hcl with 40.00 ml of 0.100 m koh? assume that the volumes of the
Digiron [165]
<span>Answer: The HCl and KOH will react until one or the other is gone. As you have a larger volume of an equal concentration of HCl, the KOH will go first. moles HCl = 0.04000 L * 0.100 M = 0.00400 moles moles KOH = 0.02500 L * 0.100 M = 0.00250 moles moles HCl left = 0.00400 - 0.00250 = 0.00150 moles Your total volume is now 65.00 mL, so the [HCl] = 0.00150 moles / 0.06500 L = 0.0231 M = [H+] pH = -log [H+] = -log (0.0231) = 1.64</span>
3 0
3 years ago
The word root for a group of microorganisms living together is a. steriliz. b. prodrom. c. coloniza. d. nosocomi.
UkoKoshka [18]

The answer is C) Coloniza.

7 0
3 years ago
650. J is the same amount of energy as A. 155 cal. B. 2720 calC. 650 cal.D. 1550 cal.
sladkih [1.3K]

Answer:

A\text{ : 155 cal}

Explanation:

Here, we want to convert J to cal

Mathematically:

1\text{ cal = 4.186 J}

Thus, to get our answer in cal, we divide the value given by 4.186

We have that as:

\frac{650}{4.186}\text{ = 155 cal}

5 0
1 year ago
What is the ratio of effusion rates of krypton and neon at the same temperature and pressure?
egoroff_w [7]
The formula we use would be the graham's law. We do as follows:

<span>E_Kr / E_Ne = sqrt ( M_Ne / M_Kr) 
</span>
<span>= sqrt ( 20.1797 g/mol / 83.798 g/mol ) </span>
<span>= sqrt (0.24081) </span>
<span>= 0.4907
</span>
Hope this answers the question. Have a nice day.
7 0
3 years ago
Read 2 more answers
Other questions:
  • Which pair are classified as chemical substances? Pick two.
    15·1 answer
  • WILL MARK BRAINLIEST!
    9·1 answer
  • How many grams of iron (density = 7.87 g/mL ) would occupy the same volume as 96.4 g of aluminum (density = 2.70 g/mL)?
    7·2 answers
  • When metallic sodium is dissolved in liquid sodium chloride, electrons are released into the liquid. These dissolved electrons a
    6·1 answer
  • Choose all the answers that apply.
    5·2 answers
  • If you mix water and vinegar together, will it form a solid?
    13·1 answer
  • Which is the most likely to be reduced
    6·2 answers
  • What will occur when potassium reacts with sulfur?
    13·1 answer
  • How many moles of solute are present in 150mL of 0.30 mol/L NaOH solution<br> ourse
    11·1 answer
  • What is the law of conservation of mass and how does it relate to chemical equations?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!