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
tester [92]
3 years ago
13

How many gram-atoms are in 120-gram sample of calcium metal? How many atoms is this?

Chemistry
1 answer:
Elden [556K]3 years ago
3 0
(sample g/1) X (1 mole/40.078(MW of Ca)) = moles of sample (moles of sample)(6.022 x 10^23( no of atoms)/ 1 mole) = # of atoms in a 120 g sample of calcium Avogadro's number=6.022x 10^23 atoms in 1 mole
You might be interested in
What mass of KNO3 would be needed to produce 18.4 liters of oxygen gas, measured at 1.50 x 10^3 kPa and 15 degrees Celsius?
Brut [27]

Answer:-

2328.454 grams

Explanation:-

Volume V = 18.4 litres

Temperature T = 15 C + 273 = 288 K

Pressure P = 1.5 x 10^ 3 KPa

We know universal Gas constant R = 8.314 L KPa K-1 mol-1

Using the relation PV = nRT

Number of moles of oxygen gas n = PV / RT

Plugging in the values

n = (1.5 x 10^3 KPa ) x ( 18.4 litres ) / ( 8.314 L KPa K-1 mol-1 x 288 K)

n = 11.527 mol

Now the balanced chemical equation for this reaction is

2KNO3 --> 2KNO2 + O2

From the equation we can see that

1 mol of O2 is produced from 2 mol of KNO3.

∴ 11.527 mol of O2 is produced from 2 x 11.527 mol of KNO3.

= 23.054 mol of KNO3

Molar mass of KNO3 = 39 x 1 + 14 x 1 + 16 x 3 = 101 grams / mol

Mass of KNO3 = 23.054 mol x 101 gram / mol

= 2328.454 grams

7 0
3 years ago
What is the wavelength of a wave having a frequency of 3.76x10^14
choli [55]

Answer:

3.76 x 1014 s-1? λ = c/ν = 3.00 x 108 m/s = 7.98 x 10-7 m 3.76 x 1014 s-1.

Explanation:

hope i helped btw i am breanna  plzz mark me brainliest

4 0
3 years ago
Convert 15.2 moles of K to atoms of K.
choli [55]

Answer:

\boxed {\boxed {\sf 9.15*10^{24} \ atoms \ K}}

Explanation:

To convert atoms to moles, Avogadro's Number must be used: 6.022*10²³.

This tells us the amount of particles (atoms, molecules, etc.) in 1 mole of a substance. In this case it is the atoms of potassium. We can create a ratio.

\frac {6.022*10^{23} \ atoms \ K }{ 1 \ mol \ K }

Multiply by the given number of moles: 15.2

15.2 \ mol \ K *\frac {6.022*10^{23} \ atoms \ K }{ 1 \ mol \ K }

The moles of potassium cancel.

15.2 *\frac {6.022*10^{23} \ atoms \ K }{ 1 }

The denominator of 1 can be ignored.

15.2 * {6.022*10^{23} \ atoms \ K }{

Multiply.

9.15344*10^{24} \ atoms \ K

The original measurement of moles has 3 significant figures, so our answer must have the same. For the number we calculated that is the hundredth place. The 3 in the thousandth place tells us to leave 5.

9.15*10^{24} \ atoms \ K

In 15.2 moles of potassium, there are <u>9.15*10²⁴ atoms of potassium.</u>

3 0
3 years ago
what tool do you have to use to precise amount of water? A meter stick B stopwatch C balance D graduated cylinder E beaker F the
Serhud [2]

Answer:

graduated cylinder

Explanation:

It shows exact volume very precisely.

8 0
3 years ago
Which describes the heliocentric model of the solar system? (1 point)
maw [93]

Answer:

D

Explanation:I alredy know this i am in 7th gread

6 0
3 years ago
Other questions:
  • For which purpose do biochemists insert human genes into bacteria?
    7·2 answers
  • A bag of potato chips is sealed in a factory near sea level. The atmospheric pressure at the factory is
    14·1 answer
  • What's the name of the process that occurs as the dry ice undergoes a phase change in the flask
    8·1 answer
  • As electrons move from the higher to the lower energy level, they release energy and ________ occurs.
    12·1 answer
  • Why is electron capture accompanied by the emission of an X-ray?
    6·1 answer
  • a. silicon<br> b. carbon <br> c. beryllium <br> d.chromium
    14·2 answers
  • This element has 80 electrons and is considered a transitional element. What am I?
    13·1 answer
  • Practice: Determine the products, balance the
    6·1 answer
  • Which scientist is credited with developing the fist scientific atomic theory
    13·1 answer
  • The Planet Venus is surrounded by a thick layer of gases. In fact the atmospheric preassure on Venus is over 90 times grater tha
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!