Answer:
The answer is below
Explanation:
The separation technique is used for separating immiscible liquids.
When separating, the stopper has to be removed when draining the lower layer so as to prevent a vacuum. If vacuum is allowed, the draining rate will reduce and stop.
The liquid should be mixed by shaking the funnel and then opening the stopcock so as the vent out gases.
When near interface between the layers, you should set your eye level so that you do not drain up to the second layer.
After completely draining the first layer, the second layer should be collected in a new flask.
After mixing the solutions in a separatory funnel, the stopper should be removed and the liquid should be mixed thoroughly and the layers allowed to separate. When you get close to the interface between the layers, get eye level with the funnel and slow the draining until the first layer is collected. Switch to a new flask to collect the second layer.
Answer:
Physical changes are changes that do not alter the identity of a substance. Chemical changes are changes that occur when one substance is turned into another substance.
Explanation:
Answer:
0.17 moles
Explanation:
In the elements of the periodic table, the atomic mass = molar mass. <u>Ex:</u> Atomic mass of Carbon is 12.01 amu which means molar mass of Carbon is also 12.01g/mol.
In order to find the # of moles in a 12 g sample of NiC-12, we will need to multiply the number of each atom by its molar mass and then add the masses of both Nickel and C-12 found in the periodic table:
- Molar Mass of Ni (Nickel): 58.69 g/mol
- Molar Mass of C (Carbon): 12.01 g/mol
Since there's just one atom of both Carbon and Nickel, we just add up the masses to find the molar mass of the whole compound of NiC-12.
- 58.69 g/mol of Nickel + 12.01 g/mol of Carbon = 70.7 g/mol of NiC-12
There's 12g of NiC-12, which is less than the molar mass of NiC-12, so the number of moles should be less than 1. In order to find the # of moles in NiC-12, we need to do some dimensional analysis:
- 12g NiC-12 (1 mol of NiC-12/70.7g NiC-12) = 0.17 mol of NiC-12
- The grams cancel, leaving us with moles of NiC-12, so the answer is 0.17 moles of NiC-12 in a 12 g sample.
<em>P.S. C-12 or C12 just means that the Carbon atom has an atomic mass of 12amu and a molar mass of 12g/mol, or just regular carbon.</em>
Answer: The diagrams show gases that are stored in two separate but similar containers. If both gases are at the same temperature, which one has the greater pressure? Gas 2 because it has more particles that are colliding.
Explanation:
The trend in ionization energy that occurs across a period on periodic table is that
Ionization energy of elements within a period generally increases from left to the right.
<u><em>explanation</em></u>
Ionization energy is energy required to remove an electron from gaseous atom or ion.
The ionization energy increase across the period because, as you move across the period (from the left to the right) the atomic radius decrease.
This make outer electrons to be closer to the nucleus and more attracted to the center.Therefore it is hard to remove electron as you move across the period.
