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
Naddika [18.5K]
3 years ago
12

How sig figs are in 28.0

Chemistry
2 answers:
Blizzard [7]3 years ago
8 0
There are 3 sig figs
Nadya [2.5K]3 years ago
5 0
There are exactly (a). 10.0 and (b). 28.0
You might be interested in
A voltaic cell utilizes the following reaction: 4Fe2+(aq)+O2(g)+4H+(aq)→4Fe3+(aq)+2H2O(l). What is the emf of this cell under st
Leviafan [203]

Answer:

0.46 V

Explanation:

The emf for the cell is given by:

Eº cell = Eº oxidation + Eº reduction

From the  given balanced chemical equation, we can deduce that Fe²⁺ has been oxidized to Fe³⁺, and O reduced  from 0 to negative 2, according to the half cell reactions:

4Fe²⁺  ⇒ Fe³⁺ + 4e⁻           oxidation

O₂ + 4H⁺ + 4 e⁻ ⇒ 2 H₂O   reduction

From reference tables for the standard reduction potential, we get

Eº red Fe³⁺ / Fe²⁺   Eºred = 0.77 V  

Eº red O₂ / H₂O      Eºred = 1.23 V

Now all we need to do is change the sign of Eº reduction for the species being oxidized ( Fe²⁺ ) and add it to Eº reduction  O₂:

Eº cell =   Eº oxidation + Eº reduction = - (0.77 V ) + 1.23 V = 0.46 V

5 0
3 years ago
Standard atmospheric pressure corresponds to the normal air pressure at sea level.
jekas [21]
Im not really sure what your asking.... <span>Standard sea-level pressure, by definition, equals 760 mm (29.92 inches) of mercury, </span>14.70 pounds per square inch<span>, 1,013.25 × 10 </span>3<span> dynes per square centimetre, 1,013.25 millibars, one standard atmosphere, or 101.325 kilopascals.

</span><span>""atmospheric pressure | Britannica.com""</span>
6 0
3 years ago
What is the mass in grams of 5.00moles of CH4?
anastassius [24]

Answer:

1. 80g

2. 1.188mole

Explanation:

1. We'll begin by obtaining the molar mass of CH4. This is illustrated below:

Molar Mass of CH4 = 12 + (4x1) = 12 + 4 = 16g/mol

Number of mole of CH4 from the question = 5 moles

Mass of CH4 =?

Mass = number of mole x molar Mass

Mass of CH4 = 5 x 16

Mass of CH4 = 80g

2. Mass of O2 from the question = 38g

Molar Mass of O2 = 16x2 = 32g/mol

Number of mole O2 =?

Number of mole = Mass /Molar Mass

Number of mole of O2 = 38/32

Number of mole of O2 = 1.188mole

6 0
3 years ago
Explain in words or using your diagrams how beryllium atoms would react with fluorine atoms.
Marysya12 [62]

Explanation:

To delineate the the nature of the bonds that would be formed between the two elements, let us first write the electronic configuration of the two species;

  Be  = 2, 2

  F  = 2, 7

 Beryllium is a metal with two valence electrons whereas fluorine is a halogen with seven valence electrons.

When Be loses two electrons it becomes isoelectronic with He;

                 Be →  Be²⁺ + 2e⁻  

Also, when fluorine gains  an electron, it becomes isoelectronic with Ne;

               F  + e⁻ →  F⁻

This loss and gain of electrons between the two elements creates an electrostatic attraction them and they enter into an electrovalent bond.

      Hence;

           Be²⁺  + 2F⁻ → BeF₂

8 0
2 years ago
Which protists lack cilia and flagella, but can still move around?
timama [110]

Answer: amoebae !

Explanation:

3 0
3 years ago
Other questions:
  • How many atoms are in 1/2 mole of calcium
    13·1 answer
  • What is one way to test whether an unknown solution is acidic or basic?
    9·1 answer
  • What is the least amount of energy that can be emitted by an excited electron in a hydrogen atom falling from an excited state d
    5·2 answers
  • The chlorination of methane occurs in a number of steps that results in the formation of chloromethane and hydrogen chloride. Th
    9·1 answer
  • Which statement about oxidation and reduction in a voltaic cell is true? Both oxidation and reduction occur at the anode.
    8·1 answer
  • 1.) Which of the following is an example of using creativity while doing background research?
    15·1 answer
  • What is the most important reason to consider ethics when conducting
    9·1 answer
  • Is PCI3 a good conductor?
    13·1 answer
  • A student made peanut butter bars by pressing a layer of graham cracker crumbs into a baking pan. Next, the student added a laye
    13·2 answers
  • How do scientists measure the idea of time so long ago?
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!