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
aev [14]
3 years ago
13

How many grams of potassium chloride are required to make 250 ml of a 0.75 m kcl solution?

Chemistry
1 answer:
DedPeter [7]3 years ago
7 0

Answer:

The solution would need 13.9 g of KCl

Explanation:

0.75 m, means molal concentration

0.75 moles in 1 kg of solvent.

Let's think as an aqueous solution.

250 mL = 250 g, cause water density (1g/mL)

1000 g have 0.75 moles of solute

250 g will have (0.75 . 250)/1000 = 0.1875 moles of KCl

Let's convert that moles in mass (mol . molar mass)

0.1875 m . 74.55 g/m = 13.9 g

You might be interested in
Low energy waves have (3 points)
Sergeeva-Olga [200]

Answer:

Low energy waves have <u>a long wavelength.</u>

Explanation:

Energy of wave is directly related to  the frequency while it is inversely proportional to the wavelength.

If any wave have high energy it will have high frequency and smaller wavelength.

If the wave have lower energy then it will have lower frequency and higher wavelength.

Mathematical relationship:

E = h. f

E = h. c/λ

E= energy

h = planck's constant

f = frequency

c = speed of light

λ = wavelength

7 0
3 years ago
Fe(NO3)2 not sure how to get the oxidation numbers of all elements
Shtirlitz [24]
You must remember that oxidation number of hydrogen in acids is always +1, oxidation number of oxygen in oxides & acids is always -2... metals has always oxidation number on plus!

group NO3 comes from HNO3...and oxidation number of whole acid group is always on minus and equal to the amount of hydrogen atoms in this acid... so oxidation number of NO3 = -1

we have 2 NO3 groups so 2*(-1) = -2 and that is the reason why oxidation number of Fe in this formula must be +2... because sum of all elements always gives 0!

Now we could count of oxidation number for nitrogen... we write HNO3 and start counting from right to left:
3*(-2) from oxygens + 1 from hydrogen = -5
so nitrogen must have +5 oxidation number... because sum all in formula must be 0.


4 0
3 years ago
BRAINLIEST PLEASE HELP!!!
Natalka [10]
Answer : first opinion and also last
Expiation : Note that these last two reactions, and 2H + 2H → 4He + γ, .Nuclear fusion is a reaction in which two nuclei are combined to form a larger nucleus. Nuclear fusion is a reaction in which two nuclei are combined, or fused, to form a larger nucleus. We know that all nuclei have less mass than the sum of the masses of the protons and neutrons that form them. The missing mass times c2 equals the binding energy of the nucleus—the greater the binding energy, the greater the missing mass.
5 0
3 years ago
HELP ME AND PLZ ANSWERED THIS ALL RIGHT PLZ
Sunny_sXe [5.5K]
<h2>Question no 1:</h2><h2>Answer:</h2>

The correct answer is option A which is Sarah is correct because genetic diversity occurs over a long period of time.

<h3>Explanation:</h3>
  • Genetic diversity is a large number of allelic combinations for a trait in specie in a population.
  • Genetic diversity is caused due to mutations or random breeding in a specie.
  • It is good for the adaptation of specie in an environment, due to diverse in genotypes and phenotype of a trait.
<h2>Question number 2:</h2><h2>Answer:</h2>

The correct answer is option B which is the species will adapt to the changes.

<h3>Explanation:</h3>
  • Adaptation to an environment means changing your body in such a way to reduce the harmful affects of changing the environment on the body.
  • For example, the long and thick fur of sheeps in a snowy area will protect them from cold.
  • If the environment changes, the first thing a specie do is an adaptation to that change in the environment.
<h2>Question 3.</h2><h2>Answer:</h2>

The correct answer is option D which is, "The spines of a cactus protect it from animals".

<h3>Explanation:</h3>
  • Adaptation to an environment means changing your body in such a way to reduce the harmful affects of changing the environment on the body.
  • For example, the long and thick fur of sheeps in a snowy area will protect them from cold.
  • So the plant of cactus was in danger due to animals. So the start growing spines in response to animals.
  • Hence the correct answer is option D.
<h2>Question 4.</h2><h2>Answer:</h2>

The correct answer is option B which is, "Marie's plant will lean toward the sun so that it can get the most sunlight".

<h3>Explanation:</h3>
  • The plant will lean towards the sun light by the mechanism of phototropism.
  • Phototropism is the mechanism of growth of the plant in a specific direction in the response of light.
  • There are two types of phototropism.
  • One is a positive phototropism in which plant grows towards the light.
  • The other is negative phototropism in which plant grows away from the light.
  • In this question,the plant will do positive tropism.
<h2>Question no. 5</h2><h2>Answer:</h2>

The correct answer is option B which is, "The dodo bird could not adapt quickly to the challenges of the environment".

<h3>Explanation:</h3>
  • Adaptation to an environment means changing your body in such a way to reduce the harmful affects of changing the environment on the body.
  • For example, the long and thick fur of sheeps in a snowy area will protect them from cold.
  • So the dodo could not adopt to the environment. For the positive adaption of survival, they should be afraid of sailors but the would not afraid of a sailor.
  • Due to which they went extinct.

Remaining questions are in attached document.






Download pdf
7 0
3 years ago
I need help on this fast plz
algol [13]

Answer:

the answer is 7 which is the atomic number of nitrogen

Explanation:

Al+Na=24

24/Oxygen (8) =3

3x rounded atomic mass of Ne (3x20) = 60

60+ 20 (# of neutrons in K)=80

80-30 (# of electrons in zinc)= 50

50/25 (the atomic number of Mn)=2

2x9 (number of protons in F)= 18

18+24 (atomic mass of Mg)=42

42/6 (number of neutrons in boron)=7

7 is the atomic number of Nitrogen (N)

3 0
3 years ago
Other questions:
  • . What is the mass, in grams, of a sample of 7.83 × 1024 atoms of helium (He)?
    5·1 answer
  • What property of liquid oxygen makes it especially difficult and potentially harmful to work with at home?
    6·1 answer
  • How many miles of barium hydroxide are in 2400 grams of Ba(OH)2
    8·2 answers
  • How many positive charges does the atom have
    10·2 answers
  • Determine the distance of closest approach (in fm) before the alpha particle reverses direction. Assume the lead nucleus remains
    7·1 answer
  • If you find the mass of a sample to be 42.1 g and the actual mass is 42.0 g. What wold be the percent error
    9·1 answer
  • Which two process do scientists think move earths lithospheric plates
    13·2 answers
  • Please Help!!<br> Qns 1b to 3
    5·1 answer
  • Hydrogen gas can be produced by reacting a mixture of methane and steam in the
    14·1 answer
  • In terms of carbon monoxide, 1 marijuana joint is the equivalent of how many cigarettes?.
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!