Answer:
False
Explanation:
The displacement method is not used to find the volume of irregularly shaped objects. Rather the opposite.
Answer:
17.76g
Explanation:
We need to write a balanced chemical equation for the reaction:
2Al(OH)3 + 3Ca(NO3)2 ——> 3Ca(OH)2 + 2Al(NO3)3
In the reaction above, it can be seen that 2 moles of aluminum hydroxide yielded 3 moles of calcium hydroxide. This is the theoretical viewpoint.
Now we need to know what actually happened. We need to calculate the actual number of moles of aluminum hydroxide reacted l. We can get this by dividing the mass by the molar mass.
The molar mass of aluminum hydroxide is 27+ 3( 16+1)
= 27 + 51 = 78g/mol
The number of moles is thus: 12.55/78 = 0.16 moles
Now if 2 moles of aluminum hydroxide gave 3 moles of calcium hydroxide, 0.16moles will give : (0.16*3)/2 = 0.24moles
Now we can calculate the mass of calcium hydroxide formed. The mass of calcium hydroxide formed is the number of moles multiplied by the molar mass.
The molar mass of calcium hydroxide is; 40 + 2(17) = 74g/mol
The mass is thus =74 * 0.24 = 17.76g
<u>Answer:</u> The boiling point of solution is 100.62°C
<u>Explanation:</u>
Elevation in boiling point is defined as the difference in the boiling point of solution and freezing point of pure solution.
The equation used to calculate elevation in boiling point follows:
To calculate the elevation in boiling point, we use the equation:
Or,
where,
Boiling point of pure water = 100°C
i = Vant hoff factor = 1 (For non-electrolytes)
= molal boiling point elevation constant = 0.512°C/m.g
= Given mass of solute = 23.6 g
= Molar mass of solute = 103.5 g/mol
= Mass of solvent (water) = 188 g
Putting values in above equation, we get:
Hence, the boiling point of solution is 100.62°C
B. Suspensions is the answer
Firstly, the chemical equation between the calcium metal and water will be:
Ca(s) + 2 H₂O(l) → Ca(OH)₂(aq) + H₂(g)
We can see from the equation the bubbles of hydrogen gas which are formed during the reaction stick to the surface of the metal and hence calcium floats on water.
The other metal that will float on the water during the reaction is magnesium which have the same chemical behavior like calcium, we can illustrate that by the chemical equation:
Mg(s) + 2 H₂O(l) → Mg(OH)₂(aq) + H₂(g)