1) balance the equation
N2 + 3 H2 → 2 NH3
2) change the given grams to moles
(42.5 g N2) / (28.01344 g N2/mol) = 1.5171 mol N2
(10.1 g H2) / (2.015894 g H2/mol) = 5.0102 mol H2
3) compare moles * remember to multiply by the coefficient of the balanced equation
1.5171 moles of N2 would react completely with 1.5171 x (3/1) = 4.5513 moles of H2, but there is more H2 present than that, so H2 is in excess and N2 is the limiting reactant.
4) from the balanced equation moles of limiting reactant to moles produced and then multiply by MW of product
(1.5171 mol N2) x (2 mol NH3 / 1 mol N2) x (17.03056 g NH3/mol) = 51.7 g NH3
5) finally subtract the moles of limiting reactant from moles of excess reactant and multiply by excess reactants MW.
((5.0102 mol H2 initially) - (4.5513 mol H2 reacted)) x (2.015894 g H2/mol) =
0.925 g H2 left over
Answer:
a. pH = 4.56
b. Change in pH = 0.85
c. Change in pH = 5.4
Explanation:
a. The pKa of lactic buffer is: 3.86.
Using Henderson-Hasselbalch formula for the lactic buffer:
pH = 3.86 + log [Lactate] / [Lactic acid]
<em>Where [] is molarity of each compound but could be taken as moles</em>
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Replacing:
pH = 3.86 + log [0.050 moles] / [0.010 moles]
<em>pH = 4.56</em>
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b. The HCl added reacts with Lactate producing lactic acid. Moles of HCl are:
5x10⁻³L * (0.5mol /L) = 0.025 moles HCl
Moles of lactate: 0.050moles - 0.025 moles = 0.025 moles
Moles lactic acid: 0.010 moles + 0.025 moles = 0.035 moles
pH = 3.86 + log [0.025 moles] / [0.035 moles]
<em>pH = 3.71</em>
Change in pH = 4.56 - 3.71 = 0.85
c. 1L of pure water has a pH of 7. 0.025 moles of HCl = 0.025 moles H⁺ in 1.005L:
0.025 mol / 1.005L = 0.0249M = [H⁺]
As pH = -log [H⁺]
pH = 1.6
Change in pH = 7.0 - 1.6 = 5.4
Explanation:
Sublimation is defined as a process in which solid state of a substance directly changes into vapor or gaseous state without undergoing liquid phase.
For example, naphthalene balls show sublimation at room temperature.
As this process does not cause any change in chemical composition of a substance. Hence, it is known as a physical process.
Similarly, when sublimes readily at . This shows change in physical state of carbon dioxide is taking place, i.e, from solid to gaseous phase.
Thus, we can conclude that when sublimes readily at then it means physical properties are usually associated with a compound that undergoes this kind of change.
So that ice would not melts and it helps to keep grip for walking or driving
Answer:
Teorema general de la hidrostática
Todo cuerpo sumergido total o parcialmente en un fluido experimenta un empuje hacia arriba igual al peso del fluido (gas o líquido) desalojado
Explanation: