Answer:
9.8 × 10⁻⁵
Explanation:
Let's consider the acid dissociation of barbituric acid.
HC₄H₃N₂O₃(aq) ⇄ C₄H₃N₂O₃⁻(aq) + H⁺(aq)
The pH is 1.93. We can find the concentration of H⁺.
pH = -log [H⁺]
[H⁺] = antilog -pH = antilog -1.93 = 0.0117 M
The concentration of the acid (Ca) is 1.4 M. We can fidn the acid dissociation constant (Ka) using the following expression.
[H⁺] = √(Ca × Ka)
[H⁺]² = Ca × Ka
Ka = [H⁺]² / Ca
Ka = (0.0117)² / 1.4
Ka = 9.8 × 10⁻⁵
Answer:
1.54 ml
2. 54 g
3. -43.7 °C
4. 97 g
5. 17.74 kJ
Explanation:
1. Volume of water that only came from the melted ice is;
Volume of water plus melted ice-volume of warm water
151 ml - 97 ml = 54 ml
2.Mass of water that came from the melted ice.
Mass=density of water * volume of water from melted ice
M=1 g/ml * 54 ml = 54 g
3. The change in temperature of warm water will be;
Lowest temperature of ice-water mixture-Temperature of warm water
ΔT=0.9-44.6 = -43.7
4. Mass of warm water will be;
Mass of warm water= density of water*volume of warm water
M=1g/ml * 97 = 97 g =0.097 kg
5.
Energy released by warm water as it cools
Q=mcΔT
Given , mass of warm water=m=97
c=4.184 j/g*°C = 4184 J/(kg.C)
Δ= - 43.7
Q=0.097*4184*43.7 =17735.56 J
17735.56/1000 =17.74 kJ
1. I think it is true?
2. Low melting points
3. True
4. Atomic number, I think it’s periods?
5. Groups?
Sorry, I might not get all of them right :(
Hope this helps you in any way!!
Answer:
Carbon contain 4 electrons in its valence shell.
Explanation:
Because, total no. of electrons in carbon are 6, so in first shell there are 2 electrons and hence 4 in valence shell.
Burning is a chemical property so (c) for #1
Sodium has one valence electron in its 3rd orbit