I believe this is the best one:
B. The volume of water will increase if cooled from 3°C to 2°C.
I don't think D) because water expands from 4°C to 0°C
"When liquid water is cooled, it contracts like one would expect until a temp of approximately 4 degrees Celsius is reached. After that, it expands slightly until it reaches the freezing point."
Answer:
The final mass of sample is 1.3 g.
Explanation:
Given data:
Half life of H-3 = 12.32 years
Amount left for 15.0 years = 3.02 g
Final amount = ?
Solution:
First all we will calculate the decay constant.
t₁/₂ = ln² /k
t₁/₂ =12.32 years
12.32 y = ln² /k
k = ln²/12.32 y
k = 0.05626 y⁻¹
Now we will find the original amount:
ln (A°/A) = Kt
ln (3.02 g/ A) = 0.05626 y⁻¹ × 15.0 y
ln (3.02 g/ A) = 0.8439
3.02 g/ A = e⁰°⁸⁴³⁹
3.02 g/ A = 2.33
A = 3.02 g/ 2.33
A = 1.3 g
The final mass of sample is 1.3 g.
Both AM and FM radio signals have the same frequencies at times.
Answer: In simplest case mass of reactants is same as mass of products.
Without thinking this question deeper, mass of ZnCl2 would be 49, but..
Explanation: Reaction should be Zn + 2 HCl ⇒ ZnCl2 + H2
Amount of zinc is 5 g / 65,38 g/mol = 0,076476 mol and amount
of Hydrogen Chloride is 50 g / 36.458 g/mol = 1,371 mol.
Althought HCl is needed 0.152 moles, zinc is an limiting reactant.
So it is possible to produce only 0.076476 mol Hydrogen and its mass
is 0.154 g. Mass of ZnCl2 would be 0.076476 mol · (65.38 + 2·35.45) =
10.42 g
Answer:
A. Occur in gaseous and liquid state
Explanation:
The choice that is not a characteristic of minerals is that minerals occur in gaseous and liquid state.
All minerals are solid inorganic compounds.
- A mineral is an inorganic compound that is formed naturally.
- They have a definite and specific chemical composition.
- Minerals are the building blocks of rocks.
- When minerals aggregates together, they form different rock types.
- There is no known mineral that is in fluid state.
- All minerals are solids.
- Examples are quartz, kaolinite, gypsum e.t.c
