Answer:
Explanation:
The graduated cylinder contains 
of water
mL is a volume unit.
Water volume = 41.7 mL
The lead ball caused an increase of volume from 41.7 mL to 96.0 mL
The new volume is the lead ball volume plus the original water volume :
Final volume = Vlead ball+ Water original volume
This is actually true if we suppose that the lead ball is fully sunken in the water.
We always must consider that the volume difference is the volume that the sunken object is occupying in the water.
Physical property- is an aspect of matter that can be observed or measured without touching changing it.
Chemical property- may only be observed by changing the chemical identity of a substance.
The difference would be that for physical property's you dont need to do anything to figure out what they are, but for chemical properties you need to change something to observe them.
Explanation:
The absolute temperature is the lowest possible temperature in the universe. At this temperature, all atoms become motionless and cease to move.
The value of the absolute zero is pegged at -273.16°C.
- It is the lowest limit of the coldness of a body.
- Nothing can be colder than a body at absolute temperature.
- Many researches are underway to take advantage of this temperature value for scientific purpose.
- Thermodynamically, all process stops at this temperature.
- When a body is brought close a body at absolute zero, it can suffer cryogenic burn due to heat transfer.
Answer:
394.05g of KO2
Explanation:
First, let us calculate the number of moles of O2 produced. This is illustrated below:
V = 100L
P = 1atm
T = 20°C = 20 +273 = 293K
R = 0.082atm.L/K /mol
n =?
PV = nRT
n = PV /RT
n = (1 x 100)/(0.082 x 293)
n = 4.16moles of O2
4KO2 + 2CO2 → 2K2CO3 + 3O2
From the equation,
4moles of KO2 produced 3moles of O2.
Therefore, xmol of KO2 will produce 4.16moles of O2 i.e
xmol of KO2 = (4.16 x 4)/3 = 5.55moles.
Converting 5.55moles O KO2 to grams, we have:
Molar Mass of KO2 = 39 + (2x16) = 39 + 32 = 71g/mol
Mass of KO2 = 5.55 x 71 = 394.05g
Therefore, 394.05g of KO2 is needed for the reaction
Answer:
2.29 × 10⁻⁴ moles
Explanation:
Data Given:
Chemical Symbol of Zinc = Zn
Mass of Zinc = 1.5 × 10⁻² g
A.Mass of Zinc = 65.38 g.mol⁻¹
The Atomic Mass of Zinc can be obtained from periodic table. While, the mass is given in statement. Also, it is important to know the symbol because some elements exist in diatomic or polyatomic forms i.e. H₂, N₂, S₈ e.t.c.
Mole is the unit used to calculate the amount of substance. It has following general forms,
Mole = Mass / M.Mass
And,
Mole = # of Particles / 6.022 × 10²³ particles.mol⁻¹
Hence, using first equation,
Moles = 1.5 × 10⁻² g / 65.38 g.mol⁻¹
Moles = 2.29 × 10⁻⁴ moles
