Density = Mass / Volume
V = 1.00 * 4.00 * 2.50 = 10 cm³
22.57 g/cm³ = Mass / 10 cm³
M = 22.57 g/cm³ * 10 cm³
M = 225.7 g
Answer: The mass of the block of osmium is 225.7 g.
Answer: when concentrations of acid and base are same, pH = pKa
PH = 12.38 pOH = 1.62
Explanation: pKa= -log(Ka)= 12.38. PH + pOH = 14.00
Depends on where the object is. On earth, moon , or somewhere without any other mass (theoretically). I think you mean how much does weigh on earth. So, the average gravitational acceleration on earth is : 9.83 m/s^2 To find out how much an object weighs, this is the formula : G=m.g where m is mass of the object g is the gravitational acceleration and G is weight. So, G = 10.9,83 = 98,3 N is the answer.
I believe the answer is concentration
Sorry if I’m wrong hope this helps