Thermal energy:
About to submit this quiz ill comment if I'm wrong
Answer:
70.6 %
Explanation:
First step, we define the reaction:
2P + 3Br₂ → 2PBr₃
We determine the moles of reactant:
35 g . 1mol / 159.8 g = 0.219 moles
We assume, the P is in excess, so the bromine is the limiting reagent.
3 moles of Br₂ can produce 2 moles of phophorous tribromide
Then, 0.219 moles may produce (0.219 . 2) /3 = 0.146 moles of PBr₃
We convert moles to mass:
0.146 mol . 270.67 g /mol = 39.5 g
That's the 100 % yield reaction, also called theoretical yield. The way to determine the % yield is:
(Yield produced / Thoeretical yield) . 100
(27.9 / 39.5) . 100 = 70.6 %
Answer:
Acoustic tractor beams use the power of sound to hold particles in mid-air, and unlike magnetic levitation, they can grab most solids or liquids even small insects. For the first time engineers have shown it is possible to stably trap objects larger than the wavelength of sound in an acoustic tractor beam. This discovery could enable the manipulation of drug capsules or micro-surgical implements within the body. The discovery could even lead to levitating humans.
Explanation:
The air pressure inside the can is lower compared to that of outside air pressure.
Explanation:
- In general, the air pressure of an already opened can will be the same as the outside pressure.
- Since the can is evacuated and remain as vacuum, so there will be no pressure difference in it.
- If the can opens, air inside the can push the top and escapes to the outside.
- This is due to high pressure experienced outside the can compare to that of lower pressure inside the can and this may even cause can to collapse itself.
Answer:
v = 534.5mL
m = 597.15g
Density = 9.23g/mL
Density = 9.125g/mL
Explanation:
Density = mass/ volume
For the first question
Density = 1.59g/mL
Mass = 834.01g
Volume = ?
Using the above formula we have 1.59 = 834.01/v
v = 834.01/1.59
v = 534.5mL
For the second question
Density =0.9167g/mL
Volume = 651.41mL
Mass =?
Using the above formula we have
0.9167 =m/651.41
Cross multiply
m = 0.9167 x 651.41
m = 597.15g
For the third question
Mass =803.44g
Volume=87.03mL
Density =?
Density = 803.44/87.03
= 9.23g/mL
For the fourth
Density = 56.85/6.23
= 9.125g/mL
