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
GREYUIT [131]
3 years ago
10

Thomas has 235 grams of K2S in the chemistry lab. How many atoms of potassium (K) are in 235 grams of the compound?

Chemistry
1 answer:
iVinArrow [24]3 years ago
4 0

The  number of atoms  of K that are in 235 g  of the compound  is

2.57 x10^24 atoms


 calculation

Step 1:  find the moles of K2S

= moles = mass/molar mass

=  235 g/110 g/mol= 2.136  moles

Step 2: multiply  2.136 moles  by no. of K atoms in K2S

= 2.136  x2 = 4.272 moles


Step 3: use the Avogadro's  law to determine number of K atoms

that is according to Avogadro's law  1 mole = 6.02 x 10^23  atoms

                                                            4.272 moles= ? atoms

by cross multiplication

= (4.272  moles x 6.02 x10^23 atoms)  / 1 mole = 2.57 x10^24 atoms

You might be interested in
Describe some conditions in Antarctica that could lead to chemical weathering
harkovskaia [24]
There's a heck ton of snow! What does that mean? It means metals that may not be water-soluble can rust.  <span />
5 0
3 years ago
Nitrogen and hydrogen combine to form ammonia in the Haber process. Calculate (in kJ) the standard enthalpy change ∆H° for the r
Kazeer [188]

Answer:

∆H° rxn = - 93 kJ

Explanation:

Recall that a change in standard in enthalpy, ∆H°, can be calculated from the inventory of the energies, H, of the bonds  broken minus bonds formed (H according to Hess Law.

We need to find in an appropiate reference table the bond energies for all the species in the reactions and then compute the result.

              N₂ (g)   +            3H₂ (g)   ⇒                          2NH₃ (g)

1 N≡N = 1(945 kJ/mol)     3 H-H = 3 (432 kJ/mol)       6 N-H = 6 ( 389 kJ/mol)

∆H° rxn = ∑  H bonds broken  - ∑ H bonds formed

∆H° rxn = [ 1(945 kJ)   + 3 (432 kJ) ] - [ 6 (389 k J]

∆H° rxn = 2,241 kJ -2334 kJ = -93 kJ

be careful when reading values from the reference table since you will find listed N-N bond energy (single bond), but we have instead a triple bond,  N≡N,  we have to use this one .

8 0
3 years ago
PLEASE HELP ME!!! NEED THE ANSWER FAST! WILL CHOOSE THE BRAINLIEST!!!
Vlad [161]
Remember that a cation will be smaller than its neutral atom, and an anion will be larger than its neutral atom. This would automatically eliminate answer choices A and D.

Also keep in mind that atomic radii decreases from left to right as you move along a periodic table. It also decreases from bottom up. 
Atomic radii increases as you move from right to left and as you go from up to down.

As bromine is higher up in the periodic table than Iodine, it would have a smaller radius. Iodine would have a larger radius.

The correct answer is B. Br
8 0
2 years ago
Which of the following elements matches the criteria below?
Tems11 [23]

Answer:

The answer to your question is below

Explanation:

1. Found in period 2. All the elements in the list are found in period 2.

a. F   This option is correct

b. Be  Beryllium is located in period two.

c. O  also oxygen is found in period 2.

d. C Carbon is found in period 2.

2.- Can gain lose 4 electrons to become its nearest stable noble gas. Only Carbon.

a. F    This option is wrong, F becomes stable when it gains 1 electron.

b. Be  Beryllium becomes stable when it loses 2 electrons.

c. O  Become stable when it gains 2 electrons.

<u>d. C </u><u>Become stable when it gains or loses 4 electrons.</u>

4 0
2 years ago
PLEASE ANSWER ASAP
marta [7]
Its an inelastic collision because the force from the bat causes it to bounce back.  It is also an elastic force because catching the ball call for the energy of the ball to be deformed and restored into the mitt.
8 0
3 years ago
Other questions:
  • What is a hygrometer?
    11·1 answer
  • What are the levels of orgamnization in a biome?
    10·1 answer
  • A sodium atom that has a mass number of 24
    6·1 answer
  • How much heat energy is required to raise the temperature of 0.368 kg of copper from 23.0 ∘C to 60.0 ∘C? The specific heat of co
    14·1 answer
  • A mixture of hept-1-yne, hept-2-yne, and hept-3-yne was hydrogenated in the presence of a platinum catalyst until hydrogen uptak
    8·1 answer
  • A 6.22-kg piece of copper metal is heated from 20.5 °C to 324.3 °C. The specific heat of Cu is 0.385 Jg-1°C-1.a.Calculate the he
    5·1 answer
  • In the following reaction, H3PO4 (aq) + H2O (l) ⇄ H2PO4– (aq) + H3O+ (aq) what happens when more H2PO4– (aq) is added to the sol
    7·1 answer
  • Temperate grasslands have trees and shrubs <br> True or false
    6·2 answers
  • Q1.
    13·1 answer
  • A student mixes sugar and water until the sugar dissolves. This an example of a<br> HELP PLS !!
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!