Answer:
Explanation:
Ketcher 01232019462D 1 1.00000 0.00000 0 5 4 0 0 0 999 V2000 -0.0330 2.2250 0.0000 C 0 0 0 0 0 0 0 0 0 0 0.8330 2.7250 0.0000 C 0 0 0 0 0 0 0 0 0 0 1.6990 2.2250 0.0000 C 0 0 0 0 0 0 0 0 0 0 0.8330 3.7250 0.0000 C 0 0 0 0 0 0 0 0 0 0 1.6990 1.2250 0.0000 C 0 0 0 0 0 0 0 0 0 0 1 2 1 0 0 0 2 3 1 0 0 0 2 4 1 0 0 0 3 5 1 0 0 0 M END
Answer:
4 g after 58.2 years
0.0156 After 291 years
Explanation:
Given data:
Half-life of strontium-90 = 29.1 years
Initially present: 16g
mass present after 58.2 years =?
Mass present after 291 years =?
Solution:
Formula:
how much mass remains =1/ 2n (original mass) ……… (1)
Where “n” is the number of half lives
to find n
For 58.2 years
n = 58.2 years /29.1 years
n= 2
or 291 years
n = 291 years /29.1 years
n= 10
Put values in equation (1)
Mass after 58.2 years
mass remains =1/ 22 (16g)
mass remains =1/ 4 (16g)
mass remains = 4g
Mass after 58.2 years
mass remains =1/ 210 (16g)
mass remains =1/ 1024 (16g)
mass remains = 0.0156g
Answer: Option B
Explanation:
Dead space is the volume of sir in the body which is inhaled but it does not takes part in the gaseous exchange this is because it does not contains alveoli.
Not all the air that is inhaled inside the body is used in the process of respiration.
The dead space in the lungs is the region which helps in conducting airways, the air is not perfused to the alveoli.
<u>Answer:</u> The correct answer is Option 1, Option 2 and Option 3.
<u>Explanation:</u>
A base is defined as the substance which releases hydroxide ion when dissolved in water.
For the given options:
- <u>Option 1:</u>
When ammonia is dissolved in water, it produces ammonium hydroxide which forms a basic solution.
- <u>Option 2:</u>
When sodium oxide is dissolved in water, it produces ammonium hydroxide which forms a basic solution.
- <u>Option 3:</u>
When lithium hydroxide is dissolved in water, it produces aqueous lithium hydroxide which forms a basic solution.
- <u>Option 4:</u>
When phosphorus pentoxide is dissolved in water, it produces phosphoric acid which forms an acidic solution.
Hence, the correct answer is Option 1, Option 2 and Option 3.
Answer:
Molecular formula of the compound = H₂CO₃
Explanation:
First, the empirical formula of the compound is determined
Percentage by mass of each element is given as shown below:
H = 3.3% ; C = 19.9%; O = 77.4%
Mole ratio of the elements= percentage mass/ molar mass
H = 3.3/ 1 = 3.3
C = 19.3/12 = 1.6
O = 77.4/16 = 4.8
whole number ratio is obtained by dividing through with the smallest ratio
H = 3.3/1.6; C = 1.6/1.6; O = 4.8/1.6
H : C : O = 2 : 1 : 3
Empirical formula = H₂CO₃
Molecular formula/mass = n(empirical formula/mass)
60 = n(2*1 + 12*1 + 16*3)
60 = n(62)
n = 60/62 = 0.96
n is approximately = 1
Therefore, molecular formula of the compound = (H₂CO₃) * 1
Molecular formula of the compound = H₂CO₃
