Answer:
0.0468 g.
Explanation:
- The decay of radioactive elements obeys first-order kinetics.
- For a first-order reaction: k = ln2/(t1/2) = 0.693/(t1/2).
Where, k is the rate constant of the reaction.
t1/2 is the half-life time of the reaction (t1/2 = 1620 years).
∴ k = ln2/(t1/2) = 0.693/(1620 years) = 4.28 x 10⁻⁴ year⁻¹.
- For first-order reaction: <em>kt = lna/(a-x).</em>
where, k is the rate constant of the reaction (k = 4.28 x 10⁻⁴ year⁻¹).
t is the time of the reaction (t = t1/2 x 8 = 1620 years x 8 = 12960 year).
a is the initial concentration (a = 12.0 g).
(a-x) is the remaining concentration.
∴ kt = lna/(a-x)
(4.28 x 10⁻⁴ year⁻¹)(12960 year) = ln(12)/(a-x).
5.54688 = ln(12)/(a-x).
Taking e for the both sides:
256.34 = (12)/(a-x).
<em>∴ (a-x) = 12/256.34 = 0.0468 g.</em>
Answer:
∆H > 0
∆Srxn <0
∆G >0
∆Suniverse <0
Explanation:
We are informed that the reaction is endothermic. An endothermic reaction is one in which energy is absorbed hence ∆H is positive at all temperatures.
Similarly, absorption of energy leads to a decrease in entropy of the reaction system. Hence the change in entropy of the reaction ∆Sreaction is negative at all temperatures.
The change in free energy for the reaction is positive at all temperatures since ∆S reaction is negative then from ∆G= ∆H - T∆S, we see that given the positive value of ∆H, ∆G must always return a positive value at all temperatures.
Since entropy of the surrounding= - ∆H/T, given that ∆H is positive, ∆S surrounding will be negative at all temperatures. This is so because an endothermic reaction causes the surrounding to cool down.
Answer:
148 g
Explanation:
Step 1: Write the balanced equation for the decomposition of sodium azide
2 NaN₃ ⇒ 2 Na + 3 N₂
Step 2: Calculate the moles corresponding to 95.8 g of N₂
The molar mass of N₂ is 28.01 g/mol.
95.8 g × 1 mol/28.01 g = 3.42 mol
Step 3: Calculate the moles of NaN₃ needed to form 3.42 moles of N₂
The molar ratio of NaN₃ to N₂ is 2:3. The moles of NaN₃ needed are 2/3 × 3.42 mol = 2.28 mol.
Step 4: Calculate the mass corresponding to 2.28 moles of NaN₃
The molar mass of NaN₃ is 65.01 g/mol.
2.28 mol × 65.01 g/mol = 148 g
At the most basic level, in order to produce oxygen and a carbohydrate (comprised of carbon, hydrogen, and oxygen), carbon dioxide must react with water as a source of hydrogen.
In order to construct carbohydrate molecules (often glucose) and release oxygen into the atmosphere, photosynthesis utilises carbon dioxide and water. Photosynthesis occurs in organelles called chloroplasts found in eukaryotic autotrophs like plants and algae.
Commonly used notation for photosynthesis is:
6CO
+ 6HO C
H
O + 6O
This indicates that the reactants, six carbon dioxide molecules and six water molecules, are transformed into a sugar molecule and six oxygen molecules, the products, by light energy being absorbed by chlorophyll.
Learn more about water here:
brainly.com/question/16630851
#SPJ4
Answer:
Option a incompressible
Explanation:
Liquids have definite volume, but indefinite shape.
Liquids take the shape of the container . When a liquid is inside a container, it will take its shape. Unlike gases, a liquid cannot change its volume to spread out and completely fill a container. Hence a liquid cannot be compressed.
Immiscible is not right because this applies only when two liquids are there
Surfectants are compounds that reduce the surface tension between two liquids or a liquid or a gas, etc.
Hence here appropriate choice is
a) incompressible
