Answer:
a weighing balance, a measuring cylinder, a spatula, a beaker/flask, and a stirrer
Explanation:
The lab apparatus that would be needed to prepare a solution of sodium chloride would be <em>a weighing balance, a measuring cylinder, a spatula, a beaker/flask, and a stirrer.</em>
The weighing balance would be used to weigh out the required amount of sodium chloride. The beaker or flask would be placed on the weighing balance and its weight zeroed. The spatula would then be sued to take out the sodium chloride from its container into the beaker till the required amount is reached. The measuring cylinder would then be used to measure out the required volume of water which would be added to the salt in the beaker. The stirrer would then be used to stir the mixture in order for the salt to dissolve.
Answer:
Copper is element number 29
4th row
11th column
Watt stands for power that is energy per unit time
To determine whether a compound is polar or nonpolar you have to take into account:
1) formation of dipoles due to the difference in electronegativities of the atoms
2) shape of the molecule to conclude whether there is a net dipole momentum.
You already, likely, know that the electronegativities of H and O are significatively different, being O more electronegative thatn H. So, you can conclude easilty that the electrons are atracted more by O than by H, thus creating two dipoles H→O
Regarding the shape, it may appear that the molecule is symmetrical, which would lead to the cancellation of the two dipoles. But that is not the true. The H2O2 is not symmetrical.
The lewis structure just show this shape
** **
H - O - O - H
** **
which is what may induce to think that the molecule is symmetrical, leading to the misconception that it is nonpolar.
But in a three dimensional arrangement you could see that the hydrogens are placed in non symmetrical positions, which leads to the formation of a net dipole momentum, and thus to a polar molecule.
The fact that H2O2 is a polar compound is the reason why it can be mixed with water and the H2O2 that you buy in the pharmacy is normally a solution in water.
So, the hydrogen peroxide is polar because the hydrogens are not placed symmetrically in the molecule, which result in a net dipole momentum.
2 C2H2 + 5 O2 --> 4 CO2 + 2 H2O
2.35 mol C2H2 - x mol O2
2 mol C2H2 - 5 mol O2
answer: 5.875 mol
