The answer is - D. are constantly in motion
These plates move back and forth and sometimes even end up going one above other
The concentration of A will be <em>0.34 mol·L⁻¹</em> after 60 min.
In a first-order reaction, the formula for the amount remaining after <em>n</em> half-lives is
![\text{[A]} = \frac{\text{[A]}_{0}}{2^{n}}\\](https://tex.z-dn.net/?f=%5Ctext%7B%5BA%5D%7D%20%3D%20%5Cfrac%7B%5Ctext%7B%5BA%5D%7D_%7B0%7D%7D%7B2%5E%7Bn%7D%7D%5C%5C)
If 
∴ ![\text{[A]} = \frac{\text{2.7 mol/L}}{2^{3.0}} = \frac{\text{2.7 mol/L}}{8.0} = \textbf{0.34 mol/L}](https://tex.z-dn.net/?f=%5Ctext%7B%5BA%5D%7D%20%3D%20%5Cfrac%7B%5Ctext%7B2.7%20mol%2FL%7D%7D%7B2%5E%7B3.0%7D%7D%20%3D%20%5Cfrac%7B%5Ctext%7B2.7%20mol%2FL%7D%7D%7B8.0%7D%20%3D%20%5Ctextbf%7B0.34%20mol%2FL%7D)
Answer:
0.693kg of CuFeS2 is needed to produce 240 grams of Cu.
Explanation:
In 1 mole of CuFeS2 is associated 1 mole of Cu.
Molar mass of CuFeS2 = 183.5 g/mol
Molar mass of Cu = 63.5g/mol
No of moles of copper present in 240g of chalcopyrite = 240/63.5 = 3.779moles
we know
1 mole of Cu → 1 mole of CuFeS2
in 3.779 moles of Cu → 3.779 moles of CuFeS2
3.779 moles of CuFeS2 = 3.779 * 183.5 = 693.45grams
CuFeS2 in kg = 0.693kg
Answer:
Specific heat of substance = 0.897 J/g.°C
Explanation:
Given data:
Specific heat of substance = ?
Mass of substance = 25.0 g
Heat absorbed = 493.4 J
Initial temperature = 12.0 °C
Final temperature = 34°C
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 34°C -12.0°C
ΔT = 22°C
493.4 J = 25 g ×c× 22°C
493.4 J = 550 g.°C ×c
c = 493.4 J / 550 g.°C
c = 0.897 J/g.°C
hope this is correct
Answer:
D
Explanation:
Iron is the fourth most abundant element, by mass, in the Earth's crust. The core of the Earth is thought to be largely composed of iron with nickel and sulfur. The most common iron-containing ore is haematite, but iron is found widely distributed in other minerals such as magnetite and taconite.
