Chemistry, 29.01.2021 14:00 jackparo9640

Determine the number of moles in each substance. a. 3.25 x 1020 atoms of lead
b. 4.96 x 1024 molecules of glucose
c. 1.56 x 1023 formula units of sodium hydroxide
d. 1.25 x 1025 copper(ll) ions

Answers: 3

Show answers

Answers

Answer from: ayoismeisalex

The number of moles in lead is 5.40 × 10⁻⁴ moles

The number of moles in glucose is 8.24 moles

The number of moles in sodium hydroxide is 0.259 moles

The number of moles in copper (II) ions is 20.76 moles

The number of moles of a substance is equal to 6.022 × 10²³ atoms. The number of moles of each given substance can be calculated by relating it to the Avogadro's constant 6.022 × 10²³ atoms.

Starting with a from the given parameters, we have:

a)1 mole of substance = 6.022 × 10²³ atomsx mole present in = 3.25 × 10²⁰ atoms of lead

Making x the subject of the formula, we have:

$\mathbf{x = \dfrac{1 \ mole \times 3.25 \times 10^{20} \ atoms }{6.022 \times 10^{23} \ atoms}}}$

x = 5.40 × 10⁻⁴ moles

b)1 mole of substance = 6.022 × 10²³ moleculesx moles present in = 4.96 ×10²⁴ molecules of glucose

$\mathbf{x = \dfrac{1 \ mole \times 4.96 \times 10^{24} \ molecules }{6.022 \times 10^{23} \ molecules}}}$

x = 8.24 moles

c) 1 mole of substance = 6.022 × 10²³ moleculesx moles present in = 1.56 × 10²³ units of NaOH

$\mathbf{x = \dfrac{1 \ mole \times 1.56 \times 10^{23} \ units}{6.022 \times 10^{23} \ units}}}$

x = 0.259 moles

d)1 mole of substance = 6.022 × 10²³ moleculesx moles present in = 1.25 × 10²⁵ copper ions

$\mathbf{x = \dfrac{1 \ mole \times 1.25 \times 10^{25} \ ions }{6.022 \times 10^{23} \ ions}}}$

x = 20.76 moles

Learn more about the number of moles here:

link

Answer from: starburst2005

a) 5.4 * 10^-4 moles

b) 8.2 moles

c) 0.26 moles

d) 20.76 moles

Explanation:

a)Since 1 mole of a substance has 6.02 * 10^23 atoms

x moles is present in 3.25 x 1020 atoms of lead

3.25 x 1020 atoms of lead/6.02 * 10^23 atoms = 5.4 * 10^-4 moles

b) Since 1 mole of a substance has 6.02 * 10^23 molecules

x moles is present in 4.96 x 1024 molecules of glucose

x = 4.96 x 1024 molecules of glucose/6.02 * 10^23 molecules = 8.2 moles

c) Since 1 mole of a substance has 6.02 * 10^23 formula units

x moles is present in 1.56 x 1023 formula units of sodium hydroxide

x = 1.56 x 1023 formula units /6.02 * 10^23 = 0.26 moles

d) Since 1 mole of a substance has 6.02 * 10^23 ions

x moles is present in 1.25 x 1025 copper(ll) ions

x = 1.25 x 1025 copper(ll) ions/6.02 * 10^23 ions = 20.76 moles

Answer from: Quest

the balanced equation for reaction of ca metal with o2 to produce cao is as below

2 ca+ o2→ 2 cao2

explanation

the reaction is balanced since the number of atoms in reactant side is equal to number of atoms in product side. for example they are 2 atom of ca in reactant side and 2 atoms of ca in the product side.

the process is a meet the requirement of redox reaction because : calcium is oxidized from oxidation state 0 to 2+ while oxygen is reduced from oxidation state 0 to 2-

Answer from: Quest

hurricanes form in warm water