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
brilliants [131]
2 years ago
13

Chemical reactions happen when _____. a.atoms attract or repel one another b.heat is created by friction c. two or more substanc

es are mixed substances are heated or d.cooled
Chemistry
1 answer:
melomori [17]2 years ago
5 0

Answer:

A

Explanation:

You might be interested in
Find the natural abundance of Si-30.
nataly862011 [7]
<span> First you need to know how many isotopes there are of silicon, and its average atomic units (look at periodic table). Then make up a system of equations to solve for it. Theres 3 stable silicon isotopes (28, 29, 30) so you will need to have 3 equations. You must be given the percent abundance of at least one of the isotopes to solve because here I can only see 2 equations (numbered down below) set x = percent abundance of si-28 y = percent abundance of si-29 z = percent abundance of si-30 since all of silicon atoms account for 100% of all silicon: x + y + z = 100% = 1 therefore: 1) x = 1 - y - z You also have 2) 28x + 29y + 30z = average atomic mass you can substitute x so that equation becomes: 28 (1 - y - z) + 29y + 30z = average atomic mass See how you have 2 variables here? You cant go on until you know the value of one isotope already or you have given a clue which you can derive the third equation</span>
5 0
3 years ago
Determine the boiling point of a 3.70 m solution of phenol in benzene. Benzene has a boiling point of 80.1°C and a boiling point
xeze [42]

Answer: The boiling point of a 3.70 m solution of phenol in benzene is 89.5^0C

Explanation:

Elevation in boiling point:

\Delta T_b=i\times k_b\times m

where,

\Delta T_b = change in boiling point

i= vant hoff factor = 1 (for benzene which is a non electrolyte )

k_b = boiling point constant = 2.53^0C/kgmol

m = molality = 3.70

T_{solution}-T_{solvent}=i\times k_b\times m

T_{solution}-80.1^0C=1\times 2.53\times 3.70

T_{solution}=89.5^0C

Thus  the boiling point of a 3.70 m solution of phenol in benzene is 89.5^0C

8 0
2 years ago
0.444 mol C2H5OH= how many molecules
brilliants [131]

Explanation:

hope it make sense to u :)

8 0
2 years ago
Consider the balanced reaction
Zina [86]

Answer:

Moles of sodium = 15.0⋅g22.99⋅g⋅mol−1 = 0.652⋅mol . Given the stoichiometry of the reaction, clearly 0.652⋅mol sodium hydroxide will result.

Explanation:

please mark me

8 0
2 years ago
If the density of mercury is 13.6 g/mL, what is the mass of 25.4 cm3 of<br> mercury?
Anettt [7]

Answer:

345.44 g or 0.34544 kg

Explanation:

Applying

D = m/V...................... Equation 1

Where D = Density of mercury, m = mass of mercury, V = Volume of mercury.

make m the subject of the equation

m = D×V................. Equation 2

From the question,

Given: D = 13.6 g/mL = 13.6 g/cm³, V = 25.4 cm³

Substitute these values into equation 2

m = 13.6×25.4

m = 345.44 g

m = 0.34544 kg

Hence the mass of mercury is 345.44 g or 0.34544 kg

4 0
2 years ago
Other questions:
  • How many electrons, protons, and neutrons are contained in the 17o?
    12·1 answer
  • A 3.82-g sample of magnesium nitride is reacted with 7.73 g of water. mg3n2 (s) + 3 h2o (â) â 2 nh3 (g) + 3 mgo (s) the yield of
    11·1 answer
  • Help im stuck on a problem
    15·2 answers
  • 2. What is the electron configuration of an electrically neutral atom of magnesium?
    13·1 answer
  • Help pls thnk you!!!!
    15·1 answer
  • An object has a mass of 441 g and a volume
    15·1 answer
  • Compare How does the horse's average speed from 60 s to 120 s compare to its average speed from 120 s to 180 s?
    8·1 answer
  • What are some questions you would ask to learn more about the toxic algal bloom in Lake Temescal? Include at least two questions
    9·1 answer
  • Round the mmHg readings to the nearest whole number. Round the kPa readings to the nearest tenth. Round the atm readings to the
    9·1 answer
  • Hello people ~
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!