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
klasskru [66]
3 years ago
15

Correct answer. 9. The mass number of an element is the number of? ​

Chemistry
1 answer:
Elis [28]3 years ago
4 0

Answer:

The mass number is defined as the total number of protons and neutrons in an atom. The number of neutrons = mass number − atomic number.

You might be interested in
200.0 mL of 3.85 M HCl is added to 100.0 mL of 4.6 M barium hydroxide. The reaction goes to completion. What is the concentratio
Ede4ka [16]

Answer:

2.387 mol/L

Explanation:

The reaction that takes place is:

  • 2HCl + Ba(OH)₂ → BaCl₂ + 2H₂O

First we <u>calculate how many moles of each reagent were added</u>:

  • HCl ⇒ 200.0 mL * 3.85 M = 203.85 mmol HCl
  • Ba(OH)₂ ⇒ 100.0 mL * 4.6 M = 460 mmol Ba(OH)₂

460 mmol of Ba(OH)₂ would react completely with (2*460) 920 mmol of HCl. There are not as many mmoles of HCl so Ba(OH)₂ will remain in excess.

Now we <u>calculate how many moles of Ba(OH)₂ reacted</u>, by c<em>onverting the total number of HCl moles to Ba(OH)₂ moles</em>:

  • 203.85 mmol HCl * \frac{1mmolBa(OH)_{2}}{2mmolHCl}= 101.925 mmol Ba(OH)₂

This means the remaining Ba(OH)₂ is:

  • 460 mmol - 101.925 mmol = 358.075 mmoles Ba(OH)₂

There are two OH⁻ moles per Ba(OH)₂ mol:

  • OH⁻ moles = 2 * 358.075 = 716.15 mmol OH⁻

Finally we <u>divide the number of OH⁻ moles by the </u><u><em>total</em></u><u> volume</u> (100 mL + 200 mL):

  • 716.15 mmol OH⁻ / 300.0 mL = 2.387 M

So the answer is 2.387 mol/L

7 0
3 years ago
Which reaction occurs spontaneously
coldgirl [10]

Answer:

Chemical Reaction

Explanation:

5 0
3 years ago
How many meters in 1000 mm
iris [78.8K]
1000 mm equals 1 meter
7 0
3 years ago
Read 2 more answers
Which of the following is NOT considered a branch of Chemistry?
mestny [16]

Answer:

Pure Chemistry -- is NOT considered a branch of Chemistry.

Explanation:

Second question is number 4.

4 0
3 years ago
Read 2 more answers
H30 + = 1x10 -10m is this acid basic or neutral
gavmur [86]

Answer:Basic

Explanation:

The pH value of the acid is 10.0 which falls within the range of basic substances. A neutral substance has a pH of 7. Any substance with pH greater than 7 is basic while pH less than 7 is for Acidic

6 0
3 years ago
Other questions:
  • A material was cooled from 100°C to 40°C. What is the temperature change?
    14·1 answer
  • Which description correctly characterizes the acidity or basicity of a solution? The higher the pH is, the more the hydroxide io
    14·2 answers
  • HELP WITH CHEMISTRY!!! PLeeeeeeeeeaaaaasssseee
    14·2 answers
  • Eukaryotes contain specialized structures that perform important cellular functions. These structures are called _______________
    11·1 answer
  • The periodic table is based on an element's
    11·1 answer
  • What is the wavelength, in nm, of radiation which has an energy if 3.371 x 10^-19 joules per photon?
    8·1 answer
  • Calculate the solubility of CaF2 in g/L (Ksp = 4.0 x 10-8). 2. What is the pH of a solution containing a hydrogen ion concentrat
    9·1 answer
  • 1What is one major difference between fossil fuels and biofuels?
    10·1 answer
  • Fill in the blanks for
    11·2 answers
  • Alan has been driving 20 mph for the last half hour. The truck next to him has been there for a while now, so Alan is
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!