Answer is: H₂O → H⁺ + OH⁻.
Water dissociates (autoionization) to form hydrogen ions (H⁺) and hydroxide (OH⁻) ions. The protons (H⁺) hydrate as hydroxonium ions( H₃O⁺).
The Kw (the ionic product for water) at 25°C is 1·10⁻¹⁴ mol²/dm⁶ or 1·10⁻¹⁴ M². Concentration of hydrogen ions and hydroxide ions in pure water are the same.
<span>0.0687 m
The balanced equation is
BaCl2 + Na2SO4 ==> BaSO4 + 2 NaCl
Looking at the equation, it indicates that there's a 1 to 1 ratio of BaCl2 and Na2SO4 in the reaction. So the number of moles of each will be equal. Now calculate the number of moles of Na2SO4 we had. Start by looking up atomic weights.
Atomic weight sodium = 22.989769
Atomic weight sulfur = 32.065
Atomic weight oxygen = 15.999
Molar mass Na2SO4 = 2 * 22.989769 + 32.065 + 4 * 15.999 = 142.040538 g/mol
Moles Na2SO4 = 0.554 g / 142.040538 g/mol = 0.003900295 mol
Molarity is defined as moles per liter, so let's do the division.
0.003900295 mol / 0.0568 l = 0.068667165 mol/l = 0.068667165 m
Rounding to 3 significant figures gives 0.0687 m</span>
I would say
D. Gravity pulled particles of dust and gas together to form planets.Hope it helped!
The brownish rock is a sedimentry rock was formed when things like sand, mud, or pebbles get laid down in layers. Eventually the layers are lithified.
The grey rock is a metamorphic rock and was when other rocks are changed because of heat or pressure. Earth movements can cause rocks to be deeply buried or squeezed. As a result, the rocks are heated and put under great pressure. They do not melt, but the minerals they contain are changed chemically, forming metamorphic rocks.
The red dots rock is an igneous rock. Igneous rock forms when hot, molten rock crystallizes and solidifies.
