How much heat is necessary to supply 2 kilograms of aluminum to raise its temperature by 20 ° C?
Answer:
36000J
Explanation:
Given parameters:
Mass of aluminum = 2kg = 2000g
Temperature rise = 20°C
Unknown:
Amount of heat needed for the temperature change = ?
Solution:
The amount of heat needed to cause this temperature rise is given as;
H = m c (T₂ - T₁)
H is the amount of heat
m is the mass
c is the specific heat of aluminum = 0.9J/g°C
Insert the parameters and solve;
H = 2000 x 0.9 x 20 = 36000J
Answer:
I think it would be b. The octet rule states that transition metal group elements tend to react so that they attain a noble gas electron configuration.
Chemical reaction (dissociation) 1: C₂O₄H₂(aq) ⇄ C₂O₄H⁻(aq) + H⁺(aq).
Chemical reaction (dissociation) 2: C₂O₄H⁻(aq) ⇄ C₂O₄²⁻(aq) + H⁺(aq).
c(C₂O₄H⁻) = c(H⁺) = x.
c(C₂O₄H₂) = 0.0269 M.
pKa₁ = 1.23.
Ka₁ = 10∧(-1.23) = 0.059.
Ka₁ = c(C₂O₄H⁻) · c(H⁺) / c(C₂O₄H₂).
0.059 = x² / (0.0269 M - x).
Solve quadratic eqaution: x = c(H⁺) = 0.02 M.
pH = -log(0.02 M) = 1.7.
The right answer is Sillicon.
Silicon (Si) is the chemical element of atomic number 14. It is the most abundant element in the earth's crust after oxygen, or 25.7% of its mass, but it is comparatively only present in relatively small quantities in the material constituting the living.
It is a semi-metal, ie it does not meet all the criteria to be defined as being a metal.
It has four free electrons in the last orbit, so it is able to form four covalent bonds. (the carbon can form 4 covalent bonds but it is not a semi-metal)
