4.48
pH=pKa+log([A-/HA])
25% deprotonated tells us that A- is .25 and that the rest (75% is protonated) thats .75.
4 = pKa + log

4 - log

= pKa
4.48=pKa
D) reacts with oxygen
All other are physical properties.
<h3><u>Answer;</u></h3>
3.64 moles
<h3><u>Explanation;</u></h3>
From the equation;
2Cu + O2 → 2CuO
Mole ratio of Cu : CuO = 2: 2 equivalent to 1: 1
Moles of CuO = 3.64 Moles
Therefore;
moles of Cu will be ;
3.64 × 1 = 3.64 moles
Moles of Cu = <u>3.64 moles </u>
The correct answer is option A.
D = M/V
The density of a substance is the ratio of its mass to its volume.
Density = mass / volume
or D = M/V
The unit of density is gram per milliliter or g/ml, when mass is expressed in gram or g and the volume is expressed in milliliter ml.
If we know the mass and volume of a substance we can calculate its density using the formula for density.