Amount of Substance (3.1.2-Phys.) Flashcards Preview

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Flashcards in Amount of Substance (3.1.2-Phys.) Deck (18)
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1
Q

Define relative atomic mass

A

Average mass of an atom compared to 1/12th the mass of an atom of carbon-12.

2
Q

Define molecular mass

A

Average mass of a molecule compared to 1/12th the mass of an atom of carbon-12.

3
Q

Define relative isotopic mass

A

Mass of an isotope compared to 1/12th the mass of an atom of carbon-12

4
Q

What is the Avogadro constant?

A

6.022 x10^23

5
Q

How do you calculate the number of particles using the Avogadro constant?

A

Moles(mass/rfm) x Avogadro number

6
Q

How do calculate mass using the Avogadro number?

A

[molecules / Avogadro no.] x RFM

7
Q

What is the ideal gas equation?

A

pV = nRT

8
Q

What are the units of each component in the ideal gas equation?

A
  • p, pressure = Pa
  • V, volume = m ^cubed
  • n, moles
  • R (given)
  • T, temp = K
9
Q

How many degrees Celsius is 0K ?

A

-273C

10
Q

How do you calculate atom economy?

A

(RFM of desires product x 100) / (Total RFM of products)

11
Q

How do you calculate percentage yield?

A

(Experimental mass/ Theoretical mass) x 100

12
Q

How do you calculate concentration (mol/dm^3)

A

moles / volume[dm^3]

13
Q

How do you calculate reacting masses?

A

1) find moles of known
2) mole ratio
3) moles of unknown

14
Q

Define ‘empirical formula’

A

The simplest whole number ratio of each atom in a compound

15
Q

What do you include in your table of calculations when working out empirical formula?

A

For each element:

  • mass (g) or %
  • moles
  • divide by smaller number
  • e.f.
16
Q

Define molecular formula

A

The actual whole number ratio of each atom in a compound

17
Q

How do you calculate molecular formula being given the empirical formula?

A

Molecular formula = (RFM of m.f.)/ (RFM of e.f.) x e.f.

18
Q

How do calculate the mass of one particle?

A

mass of 1 atom/ Avogadro