the density of a black hole is 22.61 g/cm3 i think
<span>The symbol for hydronium ion concentration is H+. </span><span>There are quite a few
relationships between [H+] and [OH−]
ions. And because there is a large range of number between 10 to 10</span><span>-15</span><span>
M, the pH is used. pH = -log[H+] and pOH = -log[OH−]. In aqueous solutions, </span><span>[H+
][OH- ] = 10-14. From here we can derive the values of each concentration.</span>
Enthalpy is a thermodynamic quantity that describes the heat content of a system, that can not be measured directly. That's why we measure change in enthaply, measured in the units joules. The statement that e<span>nthalpy change depends on the rate at which a substance is heated or cooled is false. Enthalpy change depends only on the following factors:
-</span><span>physical state of reactants and products
- quantity of reactants</span><span>
- allotropic modifications
- temperature and pressure</span><span>
</span>
<span>Igneous rock that cools very quickly when it forms may have a texture that is smooth and shiny with no visible grain.</span>
M₁ = mass of water = 75 g
T₁ = initial temperature of water = 23.1 °C
c₁ = specific heat of water = 4.186 J/g°C
m₂ = mass of limestone = 62.6 g
T₂ = initial temperature of limestone = ?
c₂ = specific heat of limestone = 0.921 J/g°C
T = equilibrium temperature = 51.9 °C
using conservation of heat
Heat lost by limestone = heat gained by water
m₂c₂(T₂ - T) = m₁c₁(T - T₁)
inserting the values
(62.6) (0.921) (T₂ - 51.9) = (75) (4.186) (51.9 - 23.1)
T₂ = 208.73 °C
in three significant figures
T₂ = 209 °C
