Answer:
A
Explanation:
3 CARBON ATOMS 8 HYDROGEN
Answer:
0.15g
Explanation:
Given parameters:
Number of molecules of water = 1.2 x 10²¹ molecules
Unknown:
Mass of SnO₂ = ?
Solution:
To solve this problem, we have to work from the known to the unknown specie;
SnO₂ + 2H₂ → Sn + 2H₂O
Ensure that the equation given is balanced;
Now,
the known species is water;
6.02 x 10²³ molecules of water = 1 mole
1.2 x 10²¹ molecules of water =
= 0.2 x 10⁻²moles
Number of moles of water = 0.002moles
From the balanced chemical equation:
2 mole of water is produced from 1 mole of SnO₂
0.002 moles of water will be produced from
= 0.001moles
To find the mass;
Mass = number of moles x molar mass
Molar mass of SnO₂ = 118.7 + 2(16) = 150.7g/mol
Mass = 0.001 x 150.7 = 0.15g
Answer:
The correct statement is that the point of initial resistance is the level of depression that will fill the pipette with the desired volume of solution.
Explanation:
The pipette can be otherwise stored vertically or horizontally, this has nothing to do with the operation, and before the operation, the dial needs to be set. Also, the plastic pipette tip should not be ejected at all, thus, no new disposable plastic tip is required for each sample.
The correct statement is that the point of initial resistance is the level of depression that will fill the pipette with the desired volume of solution.
Gets exited and moves at a faster constant speed