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Ronch [10]
3 years ago
6

How many moles of KBr are present in 8.96 x 10^21

Chemistry
1 answer:
Gelneren [198K]3 years ago
6 0

Answer:

0.015 moles

Explanation:

  • One mole of a compound contains molecules equivalent to the Avogadro's constant, 6.022 × 10^23.
  • That is, 1 mole of a compound will have 6.022 × 10^23 molecules.

In our case, We are given 8.96 x 10^21 molecules of KBr

We need to find the number of moles in 8.96 x 10^21 molecules

1 mole of KBr = 6.022 × 10^23 molecules.

8.96 x 10^21 molecules = ?

Therefore;

(1 × 8.96 x 10^21 molecules ) ÷ 6.022 × 10^23 molecules.

 = 1.488 × 10^-2 moles

 = 0.01488 moles

= 0.015 moles

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Which phase of matter is distinguished by a superheated gas that emits light?
mariarad [96]

Answer:

I think it is Plasma

Explanation:

7 0
3 years ago
A mineral consisted of 29.4% calcium, 23.5% sulfur and 47.1% oxygen. What is the empirical formula?
inessss [21]
Step  one  calculate  the  moles  of  each  element
that  is  moles= %  composition/molar  mass
molar  mass  of    Ca  =  40g/mol,     S=  32  g/mol ,   O=  16 g/mol

moles  of      Ca = 29.4 /40g/mol=0.735 moles,      S= 23.5/32  =0.734 moles,  O= 47.1/16= 2.94   moles

calculate  the mole  ratio  by  dividing   each  mole with  smallest  mole   that   is  0.734
Ca=  0.735/0.734= 1,      S=  0.734/0.734 =1,   O  = 2.94/  0.734= 4
therefore  the  emipical  formula  =  CaSO4
5 0
3 years ago
A penny has a mass of 2.50g and the Moon has a mass of ×7.351022kg, How many moles of pennies have a mass equal to the mass of t
baherus [9]
Answer: 122 moles

Procedure:

1) Convert all the units to the same unit

2) mass of a penny = 2.50 g

3) mass of the Moon = 7.35 * 10^22 kg (I had to arrage your numbers because it was wrong).

=> 7.35 * 10^22 kg * 1000 g / kg = 7.35 * 10^ 25 g.

4) find how many times the mass of a penny is contained in the mass of the Moon.

You have to divide the mass of the Moon by the mass of a penny

7.35 * 10^ 25 g / 2.50 g = 2.94 * 10^25 pennies

That means that 2.94 * 10^ 25 pennies have the mass of the Moon, which you can check by mulitiplying the mass of one penny times the number ob pennies: 2.50 g * 2.94 * 10^25 = 7.35 * 10^25.

5) Convert the number of pennies into mole unit. That is using Avogadros's number: 6.022 * 10^ 23

7.35 * 10^ 25 penny * 1 mol / (6.022 * 10^ 23 penny) = 1.22* 10^ 2 mole = 122 mol.

Answer: 122 mol
8 0
2 years ago
chegg write a net ionic equation describing the oxidation of no2 2 to no3 2 by o2 in a basic solution.
Marina86 [1]

When the same species undergoes both oxidation and reduction in a single redox reaction, this is referred to as a disproportionation. Therefore, divide it into two equal reactions.

NO2→NO^−3

NO2→NO

and do the usual changes

First, balance the two half reactions:

3. NO2 +H2O →NO^−3 + 2 H^+ + e−

4. NO2 +2 H^+ + 2e− → NO + H2O

Now multiply one or both half-reactions to ensure that each has the same number of electrons. Here, Eqn (3) x 2 results in each half-reaction having two electrons:

5. 2 NO2 + 2 H2O → 2 NO^−3 + 4H^+ + 2e−

Now add Eqn 4 and 5 (the electrons now cancel each other):

3NO2 + 2H^+ + 2H2O → NO + 2 NO−3 + H2O + 4H+

and cancel terms that’s common to both sides:

3NO2 + H2O → NO + 2NO^−3 + 2H+

This is the net ionic equation describing the oxidation of NO2 to NO3 in basic solution.

Learn more about balancing equation here:

brainly.com/question/26227625

#SPJ4

7 0
1 year ago
What the answer question
Serga [27]

Answer:

it's a trigonal bipyramidial

Explanation:

because NH3 have 3 hydrogen atoms

4 0
2 years ago
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