Answer:
after 45 days 9 g left
Explanation:
Given data:
Half life Na-24 = 15 days
Mass of sample = 72 g
Mass remain after 45 days = ?
Solution:
Number of half lives passed:
Number of half lives = time elapsed / half life
Number of half lives = 45 days / 15 days
Number of half lives = 3
At time zero total amount = 72 g
After first half life = 72 g/ 2= 36 g
At 2nd half life = 36 g/2 = 18 g
At 3rd half life = 18 g/2 = 9 g
Thus after 45 days 9 g left.
Explanation:
( a )
The decomposition reaction of KClO₃ to form diatomic oxygen gas is the following way -
2 KClO₃ ( s ) -------> 2 KCl ( s ) + 3O₂ ( g )
( b )
The reaction of solid metal of Aluminum with Iodine in the following way -
2 Al ( s ) + 3 I₂ ( s ) ------> Al₂I₆ ( s )
( c )
The reaction of sodium chloride with aqueous sulfuric acid is as follow -
2 NaCl ( s ) + H₂SO₄ ( aq ) ------> 2 HCl ( g ) + Na₂SO₄ ( aq )
( d )
The reaction of phosphoric acid with potassium hydroxide , in the following way -
H₃PO₄ ( aq ) + KOH ( aq ) ------> KH₂PO₄ ( aq ) + H₂O ( l )
Answer : Option B) The equilibrium will shift to the left to such an extent that it leads to the precipitation of solid soap.
Explanation : The equilibrium will tend to shift to left because addition of sodium chloride salt will lead to precipitate the soap as a product. The volume increase in the sodium ions because of sodium chloride addition will generate the more amount of solid soap.
Answer:
1.28 g
Explanation:
Mass of anhydrous compound/molar mass of anhydrous compound = mass of hydrated compound/ molar mass of hydrated compound
Mass of anhydrous compound = ?
Mass of hydrated compound = 2g
Molar mass of anhydrous compound= 160 g/mol
Molar mass of hydrated compound = 250 g/mol
x/160 = 2/250
250x = 2 ×160
x= 2 × 160/250
x= 1.28 g
Charles law states that volume of gas is directly proportional to temperature at constant pressure
V/T = k
where V - volume , T - temperature and k - constant
where parameters for the first instance are on the left side and parameters for the second instance are on the right side of the equation
in the question it states that the temperature has been increased from 278 K to 231 K but it should actually be temperature is decreased from 278 K to 308 K
substituting the values in the equation
V = 462 cm³
the answer should be D. 462 cm³
