Answer:
[NO₃⁻ ] = 2.596 M
Explanation:
Ca(NO₃)₂ dissolves in water according to the following equation:
Ca(NO₃)₂ ⇒ Ca²⁺ + 2NO₃⁻
The moles of Ca(NO₃)₂ that dissolve is found as followed:
(21.3 g) / (164.10 g/mol) = 0.1298... mol
The number of NO₃⁻ ions are related to the above quantity by the molar ratio:
(0.1298 mol Ca(NO₃)₂) (2NO₃⁻/Ca(NO₃)₂) = 0.2596...mol NO₃⁻
The concentration of the nitrate ions is then calculated:
[NO₃⁻ ] = (0.2596...mol) / (100.0ml) x (1000mL/L) = 2.596 M
Answer:
B. burning a piece of wood
Explanation:
The Chemical Would Be The Air Coming From The Wood While Burning It
Tell Me If Im Correct
Answer:
Volcanoes cool off the earth by emitting heat from its interior. They also add islands and for example, Hawaii was created / is made out of volcanoes. The deposits from volcanoes can also be used for building materials. Volcanic explosions have caused the atmosphere and oceans to form. Volcanic deposits also create land which is fertile.
Answer:
ΔH = -20kJ
Explanation:
The enthalpy of formation of a compound is defined as the change of enthalpy during the formation of 1 mole of the substance from its constituent elements. For H₂S(g) the reaction that describes this process is:
H₂(g) + S(g) → H₂S(g)
Using Hess's law, it is possible to sum the enthalpies of several reactions to obtain the change in enthalpy of a particular reaction thus:
<em>(1) </em>H₂S(g) + ³/₂O₂(g) → SO₂(g) + H₂O(g) ΔH = -519 kJ
<em>(2) </em>H₂(g) + ¹/₂O₂(g) → H₂O(g) ΔH = -242 kJ
<em>(3) </em>S(g) + O₂(g) → SO₂(g) ΔH = -297 kJ
The sum of -(1) + (2) + (3) gives:
<em>-(1) </em>SO₂(g) + H₂O(g) → H₂S(g) + ³/₂O₂(g) ΔH = +519 kJ
<em>(2) </em>H₂(g) + ¹/₂O₂(g) → H₂O(g) ΔH = -242 kJ
<em>(3) </em>S(g) + O₂(g) → SO₂(g) ΔH = -297 kJ
<em>-(1) + (2) + (3): </em><em>H₂(g) + S(g) → H₂S(g) </em>
<em>ΔH =</em> +519kJ - 242kJ - 297kJ = <em>-20 kJ</em>
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I hope it helps!
Answer:
Explanation:
cold and hot are temperatures
