The sample is most likely lead with lighter substances in it. Pure lead would be closer to the pure lead density, and heavier substances would make the density more, not less.
Answer:
The age of ship is 1900 years.
Explanation:
The half life period of carbon - 14 is 5730 years
Ship have 67 % of the concentration of Carbon-14
And the ship lost (100- 67 = 33%) 33% of carbon - 14.
Therefore,
The age of ship = lost percentage X half life period of carbon -14
Therefore, The age of ship is 1900 years.
Answer:
58.6 % by mass of Na₂CO₃
Explanation:
This is the reaction:
Na₂CO₃ + MgCO₃ + 4HCl → MgCl₂ + 2NaCl + 2CO₂ + 2H₂O
Let's find out the moles of CO₂ produced, by the Ideal Gases Law
1.24 atm . 1.67 L = n . 0.082 . 299K
(1.24 atm . 1.67 L / 0.082 . 299K) = n
0.0844 moles = n
Ratio is 2:1, so 2 moles of dioxide were produced by 1 mol of sodium carbonate. Let's make a rule of three:
2 moles of CO₂ were produced by 1 mol of Na₂CO₃
Then, 0.0844 moles of Co₂ would beeen produced by (0.0844 .1)/2 = 0.0422 moles of Na₂CO₃.
Let's convert this moles into mass (mol . molar mass)
0.0422 mol . 106 g/mol = 4.47 g
Finally we can know the mass percent of sodium carbonate in the mixture
(Mass of compound /Total mass) . 100 → (4.47 g / 7.63g) . 100 = 58.6 %
A negative formation enthalpy means that the reaction is exothermic, or that heat is released during the process.
(C,)
