While most constellations are only visible to us in different seasons, some are always there 24/7/365 because they are positioned close to the Polar Axis, or the Polaris.
Answer:
130ml of HCl(36%) in 4.90L solution => pH = 1.50
Explanation:
Need 4.90L of HCl(aq) solution with pH = 1.5.
Given pH = 1.5 => [H⁺] = 10⁻¹·⁵M = 0.032M in H⁺
[HCl(36%)] ≅ 12M in HCl
(M·V)concentrate = (M·V)diluted
12M·V(conc) = 0.032M·4.91L
=> V(conc) needed = [(0.032)(4.91)/12]Liters = 0.0130Liters or 130 ml.
Mixing Caution => Add 131 ml of HCl(36%) into a small quantity of water (~500ml) then dilute to the mark.
the big number describes the number ratio in a chemical equation
so for example,
2H2 + O2 --> 2H2O means
2 moles of hydrogen reacts with one mole of oxygen to form 2 moles of water
and as you know, the small (subscript) number determines the number of atoms of that element in one molecule of a compound
so I believe that drawing a normal lewis structure ( O=O ) should be correct
Answer:
B. an air-conditioning system.
Explanation:
Refrigeration is defined as a process of cooling a system to lower temperature below the surrounding temperature while the removed heat is rejected at higher temperatures.
Heat pumps use the heat output of the refrigeration process, which may also be designed to be reversible, but are otherwise similar to air conditioning units.
