Answer : The initial mass of the sample is, 31.9 mg
Explanation :
Half-life = 4 days
First we have to calculate the rate constant, we use the formula :
Now we have to calculate the initial mass of sample.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant =
t = time passed by the sample = 12 days
a = initial amount of the reactant = ?
a - x = amount left after decay process = 4 mg
Now put all the given values in above equation, we get
Therefore, the initial mass of the sample is, 31.9 mg
Co2 is made of carbon ( atomic mass: 12) and oxygen (atomic mass : 16)
First : mass of 1 C atom + mass of 2 O atom = 12+(16*2)=44 amu so 1 mole CO2 =44 grams then 2.5 mole CO2 =44*2.5 =110 grams
So the answer is 110 grams
Answer: m= 22.2 g Ne
Explanation: First find the moles of Ne using Ideal Gas Law and derive for n. So from PV= nRT the mole is derived as n = PV /RT
n = PV / RT
= 1 atm ( 25 L ) / 0.0821 L.atm /
mole.K ( 273 K )
= 1.11 moles Ne
Convert it to mass using the molar mass of Neon
1.11 moles Ne x 20 g Ne / 1 mole Ne
= 22.2 g Ne
Answer:
Yes
Explanation:
Neither Calcium nor hydrogen nor oxygen are alkali metals
- Alkali metals are Group 1 elements
- They are very soft and mellable.
- H,Li,Na,K,Cs,Fr are included in it however H is not a actual member
Here
Ca(OH)_2 is the compound
Vant Hoff factor is 3
As it's greater than 1 it's a very strong base .
The pOH of this comes around 1.5 to 1.3
So very heavy ionic dissociation
Strong Alkali
Conduction - touching hot pot
Convection - oven cycling warm air
Conduction - touching a warm coffee mug
Heat from a fire - radiation
Heat from the sun to solar panel - radiation
Warm water rising - convection