Answer: 1.3% many crosslinks as isoprene units,
Explanation:
Given:
mass pf natural rubber= 200.0g
mass of sulphur = 4.8g
molar mass of sulphur =32g/mol
molar mass of isoprene = C5H8=( 12x5) +(1x8)= 68g/mol
Solution: we first find no of moles present in each using
no of moles = 
Isoprene: 200.0g x [1mole / 68g] = 2.94moles.
Sulfur: 4.8g x [1mole / 32g] x [1 mole crosslinks / 4 moles S] = 0.0375 moles crosslinks.
to find % crosslinked units, we have
0.0375 / 2.94 = 1.3% as many crosslinks as isoprene units,
When the use of significant figures and rounding up is applied correctly the mass of the mixture will be 80.5 g.
In cases of addition or subtraction, only the last significant figure of every number is taken into account.
In 30.05, this is 5, in the hundredths. When we look at 50.0, the last significant figure is 0, and it is in the tenths. And in 0.4006, the last significant figure is 6, in the ten thousandths. Of these three, the 0 from 50.0 is in the leftmost position, which means that the last significant figure of the result needs to be in the same position (in the tenths).
Moving onto the actual algebraic operation:
30.05 g + 50.0 g + 0.4006 = 80.4506 g
As we established, the last significant figure should be in the tenths, and we will have to round up 4 to 5 (trailing numbers are greater than 0), which means that the resulting mass will be 80.5 g.
You can learn more about significant figures here:
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Answer:
The mass of 3.491 × 10¹⁹ molecules of Cl₂ of Cl₂ is 4.11 × 10⁻³ grams
Explanation:
The number of particles in one mole of a substance id=s given by the Avogadro's number which is approximately 6.023 × 10²³ particles
Therefore, we have;
One mole of Cl₂ gas, which is a compound, contains 6.023 × 10²³ individual molecules of Cl₂
3.491 × 10¹⁹ molecules of Cl₂ is equivalent to (3.491 × 10¹⁹)/(6.023 × 10²³) = 5.796 × 10⁻⁵ moles of Cl₂
The mass of one mole of Cl₂ = 70.906 g/mol
The mass of 5.796 × 10⁻⁵ moles of Cl₂ = 70.906 × 5.796 × 10^(-5) = 4.11 × 10⁻³ grams
Therefore;
The mass of 3.491 × 10¹⁹ molecules of Cl₂ of Cl₂ = 4.11 × 10⁻³ grams.
Answer:
A
Explanation:
Ductility, because it can be observed by altering the shape of the substance
