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
Oksanka [162]
2 years ago
6

Help plz i need it my mom is mad at me for not knowing this

Chemistry
1 answer:
ohaa [14]2 years ago
5 0
Lol ok ill help the answer is true and she SHOULDNT be mad at you
You might be interested in
5. Can you determine the number of neutrons in the nucleus of an atom by looking at the element's average atomic mass and the at
Shkiper50 [21]

Answer:

No you can't

Explanation:

The atomic number is the amount of protons in element's nucleus, that's one reason why. The second reason is that the atomic mass is protons and neutrons combined, their estimated value, which doesn't show how much neutrons are in an element. It does show combined, but not specifically neutrons

7 0
2 years ago
A solution is prepared from 4.5701 g of magnesium chloride and 43.238 g of water. The vapor pressure of water above this solutio
balandron [24]

Answer:

i = 2.483

Explanation:

The vapour pressure lowering formula is:

Pₐ = Xₐ×P⁰ₐ <em>(1)</em>

For electrolytes:

Pₐ = nH₂O / (nH₂O + inMgCl₂)×P⁰ₐ

Where:

Pₐ is vapor pressure of solution (<em>0.3624atm</em>), nH₂O are moles of water, nMgCl₂ are moles of MgCl₂, i is Van't Hoff Factor, Xₐ is mole fraction of solvent and P⁰ₐ is pressure of pure solvent (<em>0.3804atm</em>)

4.5701g of MgCl₂ are:

4.5701g ₓ (1mol / 95.211g) = 0.048000 moles

43.238g of water are:

43.238g ₓ (1mol / 18.015g) = 2.400 moles

Replacing in (1):

0.3624atm = 2,4mol / (2.4mol + i*0.048mol)×0.3804atm

0.3624atm / 0.3804atm = 2,4mol / (2.4mol + i*0.048mol)

2.4mol + i*0.048mol = 2.4mol / 0.9527

2.4mol + i*0.048mol = 2.5192mol

i*0.048mol = 2.5192mol - 2.4mol

i = 0.1192mol / 0.048mol

<em>i = 2.483</em>

<em />

I hope it helps!

4 0
3 years ago
which of the following substances is least able to cross the blood-brain barrier.)a. waterb. sodium ionsc glucosed. white blood
ivolga24 [154]

Answer:

d. white blood cells

Explanation:

It is the white blood cells that have the least tendency to cross the blood- brain barrier.

Blood- brain barrier is psychological barrier and restricts substances that circulate into the blood from crossing over the central nervous system.

Water, glucose as well as sodium ions can easily cross the barrier. As these are good for body supply energy to the brain.

8 0
3 years ago
The density of water at 40°c is 0.992 g/ml. what is the volume of 3.45 g of water at this temperature?
wariber [46]
3.45÷0.992=3.48ml
...
8 0
3 years ago
How many grams of CaCl2 are needed to make 277.8g of a solution that is 31.5% (m/m) in water? Note that mass is not technically
Sveta_85 [38]

<u>Answer:</u> The mass of calcium chloride present in given amount of solution is 87.5 g

<u>Explanation:</u>

We are given:

Mass of solution = 277.8 grams

Also, 31.5 % (m/m) of calcium chloride in water. This means that 31.5 g of calcium chloride is present in 100 g of solution.

To calculate the mass of calcium chloride in the given amount of solution, we use unitary method:

in 100 g of solution, the mass of calcium chloride present is 31.5 g

So, 277.8 g of solution, the mass of calcium chloride present is \frac{31.5}{100}\times 277.8=87.5g

Hence, the mass of calcium chloride present in given amount of solution is 87.5 g

8 0
3 years ago
Other questions:
  • Condors are related to vultures and feed on carrion, or dead animals.
    13·1 answer
  • PLEASE HELP ME!!!!!!!!!!!!!!!!!!!!!!!!!
    12·1 answer
  • 1. Which occurs when the forward and reverse reactions occur at the same rate?
    5·2 answers
  • This is the normal nucleotide sequence on a DNA strand:
    14·2 answers
  • When children are young and go to the doctor, the doctor will give them booster shots. This re-exposes the children to a dead po
    5·2 answers
  • Empirical formula for 70.9% K and 29.1% S
    13·1 answer
  • How many molecules are in 3 moles of potassium bromide (KBr)
    13·1 answer
  • Describe the process to electroplating with the help of an activity <br>​
    12·1 answer
  • What is the independent variable for this experiment?
    14·1 answer
  • Libr (s) → li (aq) br- (aq) δh = -48. 8 kj/mol in a coffee-cup calorimeter you dissolve 21. 4 g of this salt in 111 g of water a
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!