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
coldgirl [10]
3 years ago
13

Dumbledore is pleased with your progress. snape is, as always, somewhat indifferent. however, they both feel a gas phase density

problem should come next. calculate the density of helium gas at 25.0◦c and at a pressure of 1521 mmhg. express your answer in g/l.
Chemistry
1 answer:
Zarrin [17]3 years ago
8 0
Answer is: 0,327 g/l.
<span>Ideal gas law: pV = nRT.
</span><span>V - volume, the amount of space occupied by the gas.
</span><span>p - pressure ,1 atm = 760 torr = 760 mmHg.
</span><span>n - amount of substance.
</span>T - temperature, 273 K = 0°<span>C. T = 25 + 273 = 298K.
</span>R - ideal gas constant,<span> R = 0,08206 L</span>·atm/mol·K<span>.
</span>d(He) = M·p ÷ R·T.
d - density.
M - molar mass.
d(He) = 4g/mol · 2atm ÷  298K · 0,08206 L·atm/mol·K = 0,327 g/l.
You might be interested in
What is 0.00034 in exponential form
Verizon [17]

Answer:

3.4  ×  10 ^− 4

Explanation:

Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the  

10 . If the decimal is being moved to the right, the exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.

7 0
3 years ago
What is the basic difference between exergonic and endergonic reactions? Group of answer choices Exergonic reactions release ene
alekssr [168]

Answer: the basic difference is Exergonic reactions release energy and an endergonic reactions absorb energy .

HOPE THIS HELPS!!!

3 0
3 years ago
Calculate the molarity of a solution of Nach if it contains 7.2.g Nach in 100.0 mL of solution. andver: m Nach . .
Norma-Jean [14]

Answer:

1.23 M

Explanation:

Molarity of a substance , is the number of moles present in a liter of solution .

M = n / V

M = molarity  

V = volume of solution in liter ,

n = moles of solute ,

Moles is denoted by given mass divided by the molecular mass ,  

Hence ,  

n = w / m

n = moles ,  

w = given mass ,  

m = molecular mass .

From the question ,

w = given mass of NaCl = 7.2 g

As we know , the molecular mass of NaCl = 58.5 g/mol

Moles is calculated as -

n = w / m  =  7.2 g / 58.5 g/mol = 0.123 mol

Molarity is calculated as -

V = 100ml = 0.1 L            (since , 1 ml = 1/1000L )

M = n / V  =  0.123 mol / 0.1 L = 1.23 M

5 0
3 years ago
At what point in time (A ,B or C) is the reaction the fastest? How do you know?
gladu [14]
Don’t click that link EVER, they try to use your camera fsr
4 0
3 years ago
A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. how much calcium is contained in 45.0 g of c
kolbaska11 [484]

In a sample of pure calcium fluoride of mass 15.0 g, 7.70 g of calcium is present. First convert the mass into number of moles as follows:

n=\frac{m}{M}

Here, m is mass and M is molar mass.

Molar mass of Ca is 40 g/mol, putting the values,

n=\frac{7.70 g}{40 g/mol}=0.1925 mol

Similarly, molar mass of CaF_{2} is 78.07 g/mol thus, number of moles will be:

n=\frac{15.0 g}{78.07 g/mol}=0.1921 mol.

Thus, 0.1921 mol of CaF_{2} have 0.1925 mol of Ca, or 1 mole of CaF_{2} will have approximately 1 mole of Ca.

Now, mass of Ca needs to be calculated in 45.0 g of CaF_{2}. Converting mass into number of moles first,

n=\frac{45.0 g}{78.07 g/mol}=0.5764 mol

Thus, number of moles of Ca will also be 0.5764 mol, converting number of moles into mass,

m=n\times M=0.5764 mol\times 40 g/mol=23.06 g

Therefore, mass of Ca will be 23.06 g.

6 0
3 years ago
Other questions:
  • A radioisotope has a half-life of 12 days. If a sample is measured to contain 5 grams of radioisotope, how much time has passed
    9·1 answer
  • How can valence electrons be used to predict the type of compounds formed?
    13·1 answer
  • How does active transport differ from passive transport
    14·2 answers
  • 1.which of newton's laws describe the mathematical relationship between force, mass, and acceleration
    14·1 answer
  • 1. Describe what an irreversible change is.
    11·2 answers
  • Balance each of these equations.
    12·1 answer
  • .Which of the following elements has the lowest first ionization energy? a.Li
    13·1 answer
  • How does lemon juice stop an apple from turning brown?
    5·1 answer
  • Which element makes up most of the air we breathe.
    8·1 answer
  • What is the least measurement of black hole, ​
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!