Answer:
If you turn the lights on and off rapidly, then the bulb will burn out faster. It's some sort of prediction
question 1
moles = mass/molar mass of Al(OH)3
convert Kg to g
that is 1.09 x 1000=1090g
moles is therefore=1090g/78(molar mass of Al(OH)3)= 13.974 moles
question 2
moles=2.55g/327.2(molar mass of Pb(CO3)2= 7.79 x 10^-3 moles
from avogadro constant
1moles=6.02 x10^23 formula units
what about 7.79 x 10 ^-3
={(7.79 x 10^-3)moles x ( 6.02 x10^23)} /1 mole=4.69 x10^21 formula units
Answer:
B: increase.
Explanation:
When we are considering two gases A and B in a container at room temperature .
We have to find the change on rate of reaction when the number of molecules of gases A is doubled
Let [A]=a and [B]=b
A+B product
Rate of reaction
We know that concentration is increases with increase in number of moles
When the number of molecules of gases A is doubled then concentration of gases A increases.
Therefore ,[A]=2a
Rate of reaction
Hence, the rate of reaction is 2 times the initial rate of reaction.Therefore, the rate of reaction will increase when the number of molecules of gases A is doubled.
Answer: B: increase.
Answer:
Option (b) 0.67 M
Explanation:
The following Data were obtained from the question:
Mole of MgCl2 = 0.5 mole
Volume of solution = 750mL
Molarity of MgCl2 =?
Next, we shall convert the volume given from mL to L. This is illustrated below:
1000mL = 1L
Therefore 750mL = 750/1000 = 0.75L
Now we can obtain the molarity of MgCl2 as follow:
Molarity is defined as the mole of solute per unit litre of the solution i.e
Molarity = mole /Volume
Molarity = 0.5/0.75
Molarity of MgCl2 = 0.67 M
The correct answer is D. Cesium chloride is held together by ionic bonding. This substance is a salt like sodium chloride. It is also soluble in water. When it dissociates, it forms into cesium ions and chloride ions.