Answer:
pH → 7.46
Explanation:
We begin with the autoionization of water. This equilibrium reaction is:
2H₂O ⇄ H₃O⁺ + OH⁻ Kw = 1×10⁻¹⁴ at 25°C
Kw = [H₃O⁺] . [OH⁻]
We do not consider [H₂O] in the expression for the constant.
[H₃O⁺] = [OH⁻] = √1×10⁻¹⁴ → 1×10⁻⁷ M
Kw depends on the temperature
0.12×10⁻¹⁴ = [H₃O⁺] . [OH⁻] → [H₃O⁺] = [OH⁻] at 0°C
√0.12×10⁻¹⁴ = [H₃O⁺] → 3.46×10⁻⁸ M
- log [H₃O⁺] = pH
pH = - log 3.46×10⁻⁸ → 7.46
a.
A substance's specific heat tells you how much heat is required to increase the temperature of 1 g of that substance by 1°C.
The equation that establishes a relationshop between heat and change in temperature is
q = m • c • ∆T, where
q - heat absorbed
c - the specific heat of the substance, in your case of water
ΔT - the change in temperature, defined as the difference between the final temperature and the initial temperature
so:
q = 1.00 g • 4.18 J/g×°C • (75.0 - 38.5)°C
q = 152,57 J
just apply this formula for all exercises
Empirical formula is the simplest formula showing the simplest ratio of atoms in a compound. Calculated as shown;
we start by calculating the number of moles of each atom;
moles of nickel = 9.11 g ÷ 58.7 g = 0.155 moles
moles of fluorine = 5.89 g ÷ 19 g = 0.31 moles
Then we get the ratio of the moles of nickel to that of flourine
That is 0.155 : 0.31 (dividing by the smallest)
0.155/0.155 : 0.31/0.155
we get 1:2 ( the simplest ratio)
Therefore the empirical formula is nif2
Answer:
C because 77.0 CsF
Explanation:
That is the correct answer because I have that homework and i got it right
Answer:
7. 4H₂O
Elements: Hydrogen, Oxygen
Number of molecules: 4
Number of elements: 8 H, 4 O
Number of Atoms: 12
Explanation:
The elements are determined by the their symbol i.e. H = hydrogen.
The number of molecules is determined by the coefficient ( the number in front of everything, in this case 4).
The number of elements is determined by the coefficient and the subscripts. Multiply the coefficient by the subscript after each element. When there is no subscript, it is equal to 1. 4H₂ = 4x2 = 8; 4O = 4x1 = 4.
The number of atoms is all the individual elements added together. 8+4 = 12.
