Answer: -
2.5 moles of calcium atoms are in 2.5 moles of calcium carbonate CaCO₃
Explanation: -
In order to solve such types of problems, the first step would be to write the chemical formula of the compound.
The chemical formula of calcium carbonate = CaCO₃
The chemical symbol of Calcium is Ca.
From the formula of calcium carbonate we can see that
1 mole of CaCO₃ has 1 mole of Ca
2.5 mole of CaCO₃ has 
= 2.5 mol of Ca.
∴2.5 moles of calcium atoms are in 2.5 moles of calcium carbonate CaCO₃
Answer: According to Boyle's Law, if the temperature remains constant, doubling the pressure will halve the volume of the gas.
Explanation:
Answer:
gamma rays have a different wavelength then light waves (visible waves excluding ultraviolet) gamma rays are released from radioactive substances along with alpha and beta particles.
Explanation:
Gama rays are a separate wavelength their are many different wavelengths look up a spectrum chart on the internet to better understand.
Answer:
<em>8,459x10⁻³ M of Cr₂O₇²⁻</em>
Explanation:
The equation for the reaction of Fe²⁺ with Cr₂O₇²⁻ is:
Cr₂O₇²⁻(aq) + 6Fe²⁺(aq)+14H₃O⁺(aq) → 2Cr³⁺(aq) + 6Fe³⁺(aq)+21H₂O(l)
The moles of Fe²⁺ that you required for a complete reaction of Cr₂O₇²⁻ are:
0,01515 L ×
= 2,0301x10⁻³ moles of Fe²⁺
By the equation of the reaction, 1 mol of Cr₂O₇²⁻ reacts with 6 moles of Fe²⁺, thus, moles of Cr₂O₇²⁻ are:
2,0301x10⁻³ moles of Fe²⁺×
= 3,3835x10⁻⁴ moles of Cr₂O₇²⁻
The molarity is:
= <em>8,459x10⁻³ M of </em>Cr₂O₇²⁻
I hope it helps!
We can use combined gas law,
PV/T = k (constant)
Where, P is the pressure of the gas, V is volume of the gas and T is the temperature of the gas in Kelvin.
For two situations, we can use that as,
P₁V₁/T₁= P₂V₂/T₂
P₁ = 795 mm Hg
V₁ = 642 mL
T₁ = (273 + 23.5) K = 296.5 K
P₂ = ?
V₂ = 957 mL
T₂ = (273 + 31.7) K = 304.7 K
From substitution,
795 mm Hg x 642 mL / 296.5 K = P₂ x 957 mL / 304.7 K
P₂ = 548.072 mm Hg
760 mmHg = 1 atm
548.072 mm Hg = 1 atm x (548.072 mmHg / 760 mmHg)
= 0.721 atm
Pressure of Oxygen gas is 0.721 atm.
Answer is "A"
Here, we made an assumption that oxygen gas has an ideal gas behavior.
