Answer:
Option A. The specific heat is 0.897 J/gºC, The Substance is aluminum.
Explanation:
We'll begin by calculating the change in temperature of the substance. This can be obtained as follow:
Initial temperature (T₁) = 20.0 °C
Final temperature (T₂) = 40.0 °C
Change in temperature (ΔT) =?
ΔT = T₂ – T₁
ΔT = 40 – 20
ΔT = 20 °C
Finally, we shall determine the specific heat capacity of the substance. This can be obtained as follow:
Mass (M) = 136 g
Change in temperature (ΔT) = 20 °C
Heat (Q) absorbed = 2440 J
Specific heat capacity (C) =?
Q = MCΔT
2440 = 136 × C × 20
2440 = 2720 × C
Divide both side by 2720
C = 2440 / 2720
C = 0.897 J/gºC
Comparing the specific heat capacity (i.e 0.897 J/gºC) of the substance with those in the table above, the substance is Aluminum.
Thus, option A gives the correct answer to the question.
Answer:
0,040 M
Explanation:
The global reaction of the problem is:
Al(OH) (s) + OH⁻ ⇄ Al(OH)₂⁻(aq) K= 40
The equation of equilibrium is:
K = ![\frac{[Al(OH)_{2} ^-]}{[Al(OH)][OH^-]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BAl%28OH%29_%7B2%7D%20%5E-%5D%7D%7B%5BAl%28OH%29%5D%5BOH%5E-%5D%7D)
The concentration of OH⁻ is:
pOH = 14 - pH = <em>3</em>
pOH = -log [OH⁻]
[OH⁻] = 1x10⁻³
Thus:
40 = ![\frac{[Al(OH)_{2} ^-]}{[Al(OH)][1x10^{-3}]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BAl%28OH%29_%7B2%7D%20%5E-%5D%7D%7B%5BAl%28OH%29%5D%5B1x10%5E%7B-3%7D%5D%7D)
<em>0,04M = ![\frac{[Al(OH)_{2} ^-]}{[Al(OH)]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BAl%28OH%29_%7B2%7D%20%5E-%5D%7D%7B%5BAl%28OH%29%5D%7D)
</em>
This means that 0,04 M are the number of moles that the solvent can dissolve in 1L, in other words, solubility.
I hope it helps!
Alpha particles, also called alpha ray or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a <u>helium-4 nucleus. </u>They are generally produced in the process of alpha decay, but may also be produced in other ways.
Composition: 2 protons, 2 neutrons
Mass: 6.644657230(82)×10−27 kg; 4.0015061...
Electric charge: +2 e
Symbol: α, α2+, He2+
The new volume of the balloon : V₂ = 4.89 L
<h3>Further explanation</h3>
Given
V₁ = 4.96 L
T₁ = 6 + 273 = 279 K
T₂ = 2 + 273 = 275 K
Required
The new volume
Solution
Charles's Law
When the gas pressure is kept constant, the gas volume is proportional to the temperature
Input the value :
V₂=V₁.T₂/T₁
V₂ = 4.96 x 275 / 279
V₂ = 4.89 L
because it makes the environment to be present with chemical bonds
