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
Vsevolod [243]
2 years ago
7

What observation would you look for to tell if a reaction was endothermic?

Chemistry
1 answer:
horsena [70]2 years ago
5 0

Exothermic reactions release heat into their surroundings and endothermic reactions absorb heat and are cool. I believe the correct answer is D.

You might be interested in
You are experimenting to find out if fertilizer makes a plant grow taller. What would be an appropriate control group for this e
leonid [27]

Answer:

If plants are given nitrogen fertilizer, then they will grow taller. ... Factors in an experiment that a scientist PURPOSELY Changes (manipulated) Control Group ... to test various amounts of fertilizer to find out what amount makes plants grow

Explanation:

3 0
3 years ago
Given the reaction: Ca + 2H2O → Ca(OH)2 + H2 What is the total number of moles of Ca needed to react completely with 4.0 moles o
DiKsa [7]

<u>Answer:</u> The number of moles of calcium metal required is 2.0 moles.

<u>Explanation:</u>

We are given:

Moles of water reacted = 4.0 moles

The given chemical reaction follows:

Ca+2H_2O\rightarrow Ca(OH)_2+H_2

By Stoichiometry of the reaction:

2 moles of water is reacted with 1 mole of calcium metal

So, 4.0 moles of water will react with = \frac{1}{2}\times 4.0=2.0mol of calcium metal

Hence, the number of moles of calcium metal required is 2.0 moles.

6 0
3 years ago
Read 2 more answers
What percentage of carpet is calcium carbonates?
e-lub [12.9K]

Answer:

the percentage of carpet is calcium carbonates is 12.456734190

5 0
3 years ago
What effect does atmospheric pressure and altitude have on the boiling point of water?
NeTakaya
The temperature change.
5 0
3 years ago
A mixture of c2h2 and ch4 has a total mass of 230.9 g. when this mixture reacts completely with excess oxygen, the co2 and h2o p
Salsk061 [2.6K]
Interesting problem. Thanks for posting.

C2H2 + (3/2)02 ====>  H2O + 2CO2
CH4 +  2O2 =====> 2H2O + CO2

The molar mass of C2H2 = 2*12 + 2*1 = 26
The molar mass of CH4 = 1*12 + 4*1 = 16

The number of moles of C2H2 = x
The number of moles of  CH4 = y
26x + 16y = 230.9 grams

For water we get (from the C2H2). Water has a molar mass of 2*1 + 16 = 18

x*18 See the balanced equation to see what it is the same number of moles as C2H2
From the methane we get
y*18
2*y* 18. Again see the balanced equation to see where that 2 came from.
18x + 36y is the total amount of water. 

Now for the CO2. CO2 has a molar mass of 12 + 2*16 = 44
From C2H2  we get 2*44*x = 88x grams of CO2
From CH4 we get 1*y*44 grams of CO2
88x + 44y for CO2

Now we total to get the grand total of water and CO2
18x + 44y + 88x + 44y = 972.7 grams total.
106x + 88y =  972.7

Two equations, two unknowns, we should be able to solve this problem
26x + 16y = 230.9
106x + 88y = 972.7

I'm not going to go through the math unless you request me to do so. 
x = 8.03 moles
y = 1.38 moles 

The initial amount of C2H2 was 8.03 * 26 = 208.78
The initial amount of CH4 was 16*1.38 = 22.08
The total (as a check is 230.86 which is pretty close to the given amount.
So Methane's mass in the initial givens was 22.08 grams.
6 0
3 years ago
Other questions:
  • A gas has a volume of 31.2 L at a temperature of 28 degrees Celsius and a pressure of 82.6 kPa. How many moles are in the sample
    11·1 answer
  • Which statement is TRUE about polar covalent bond?
    14·1 answer
  • What is the solution to the proportion 3/m = 12/15
    8·2 answers
  • A compound has an empirical formula of C2H5. What is true about this empirical formula?
    9·1 answer
  • Many tall buildings have a
    9·1 answer
  • How is the Bohr atomic model different from the plum-pudding model?
    9·2 answers
  • Based on the information in the graph, which statement best applies to a gas?
    12·2 answers
  • What are the four most important elements on earth?
    12·2 answers
  • If I have an unknown quantity of gas at a pressure of 1.2 atm, a volume of 77 liters, and a temperature of
    9·1 answer
  • F(x) = x3 + ax2 + bx + c
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!