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
topjm [15]
3 years ago
9

If you weighed out 0.38 g of calcium and reacted it with an excess of hcl, how many moles of h2(g) would you expect to produce?

Chemistry
1 answer:
Hitman42 [59]3 years ago
4 0
Answer is: 0,0095 mol of hydrogen gas will be produced in reaction.
Chemical reaction: Ca + 2HCl → CaCl₂ + H₂.
m(Ca) = 0,38 g.
n(H₂) = ?
n(Ca) = m(Ca) ÷ M(Ca).
n(Ca) = 0,38 g ÷ 40 g/mol
n(Ca) = 0,0095 mol.
from reaction: n(Ca) : n(H₂) = 1 : 1.
n(H₂) = n(Ca) = 0,0095 mol.
n - amount of substance.
You might be interested in
At standard temperature and pressure, 1 mole of gas has what volume? A. 2.4 liters B. 22.4 liters C. 42.4 liters D. 76.6 liters
LekaFEV [45]

Answer: B.22.4 liters

Explanation:

When we attribute to a certain fixed mass of a given gas a fixed number of molecules. Avogadro considered that the mass of 36g of oxygen at any temperature and pressure would have a fixed number of molecules to which he called 1 mol of molecules. So by definition 1 mole of molecules would have a number of molecules equal to that present in 36 g of oxygen. The occupied volume by one mole of molecules at a given temperature and pressure is called molar volume and consists in 22,4 Liters. The molar volume matches the Avogadro Hypothesis (created in 1811 by Amedeo Avogadro), where equal volumes of different gases, at the same temperature and pressure, have even number of moles.

8 0
3 years ago
consider an exceptionally weak acid, HA, with Ka= 1 x 10-20. you make 0.1M solution of the salt NA. what is the pH.
iogann1982 [59]

Answer:

pH=10.5

Explanation:

Hello,

In this case, the dissociation of the given weak acid is:

HA\rightleftharpoons H^++A^-

Therefore, the law of mass action for it turns out:

Ka=\frac{[H^+][A^-]}{[HA]}

That in terms of the change x due to the reaction extent is:

1x10^{-23}=\frac{x*x}{0.1-x}

Thus, by solving with the quadratic equation or solver, we obtain:

x=31.6x10^{-12}M

Which clearly matches with the hydrogen concentration in the solution, therefore, the pH is:

pH=-log(-31.6x10^{-12})\\pH=10.5

Regards.

5 0
3 years ago
What are the similarities and differences between ionic and covalent bonds?
ohaa [14]

Answer:

Explanation:

Similarities.

Both Ionic and covalents bond produce exothermic reactions.

They are both neutral.in Ionic bonds, the two opposite charge will terminate each other and in covalent, the neutral molecules tend to share electrons.

Difference

Ionic bonds have high polarity while covalent have low.

Ionic bonds have no definite shape, covalent have.

Ionic have high melting points, covalent have low.

Io ic have high boiling point, covalents have low.

5 0
2 years ago
Which phrase describes a hypothesis? a. reviewing information related to the problem b. testing a factor, or variable, in an exp
monitta

Answer:

c. suggesting a solution to a problem after studying it carefully

Explanation:

Hypothesis generally refers to an assumption made. This assumption can either be true or false. It is a reasoning presented in order to explain a phenomenon and is the starting point for further investigation.

Among the options, the closest that best describes it is option C.

4 0
3 years ago
An exothermic reaction is a chemical reaction where heat is
ch4aika [34]
Emitted/given off. exo is a way to remember that is is going away. think of a flame. the heat is emitted off onto you.
3 0
2 years ago
Read 2 more answers
Other questions:
  • In the vertical columns of the periodic table, as the atomic numbers increase:
    12·2 answers
  • Which scientific tools are used by life scientists
    6·1 answer
  • PLEASE HELP!!!! Which is a correct statement of Newton's second law? Question 1 options: Every action has an equal and opposite
    6·2 answers
  • What is described by the VSEPR theory?
    13·1 answer
  • Who discovered by aluminun____________________in_______________
    13·1 answer
  • A substance made up of two or more types of atoms that are NOT chemically combined is called a(n)
    7·1 answer
  • A man can walk at a speed of 20 mi/day. How far will he walk in 5 days?
    11·2 answers
  • What is the relative mass of an electron?<br> 1+<br> -1<br> 2<br> 0
    7·2 answers
  • How many atoms of each element are in NaCI?
    12·1 answer
  • Design a controlled experiment to test your hypothesis. A controlled experiment is one that only tests one variable. All other v
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!