<span> first calculate the moles of every compound used
n NH3 = (0.160 mol /L )(0 .360 L) = 0.058 moles NH3
which is equal to moles NH4OH
0.058 moles NH4OH.
n MgCl2 = (0.12 mol /L)( 0.10 liters = .012 moles MgCl2
reaction 2 NH3.H20 or 2 NH4OH + MgCl2 --> Mg(OH)2(s) + 2 NH4+ + 2Cl-
Molarity of Mg++ =(0.012 moles Mg+) / 0.46 liters = 0.026 Molar Mg++
Molarity OH= (0.058 moles OH-)/ 0.46 liters = 0.126 molar OH-
the limiting reactant is Mg ++ because it is lesser than the molarity of OH-
Now the challenge is to drive the OH-) concentration down so low that Mg(OH)2 will not precipitate out.
Ksp = 1.8 x 10^-11 = (Mg)(OH-)^2
Mg++ concentration to be .026 Molar, so let X = the (OH-) concentration
1.8 x l0^-11 = (0.026)(X)^2
(X)^2 = ( 1.8 x 10^-11) / (0.026)
X^2 = 6.92 x 10^-10
X =
2.63 x l0^-5 moles (OH-)/ L
this is the concentration where solid will form
so we need to lower the (OH-) which is
0.126 molar OH- down to 2.63 x 10^-5 molar OH- by adding NH4+ ions.
(0.126 moles/liter 0H-) - (2.63 x l0^-5 molar OH- ) = 0.123 moles per liter
OH- to be neutralized by adding NH4+
since the mole ratio is 1 : 1 then </span><span> 0.123 moles per liter NH4+ concentration to neutralize the </span><span><span> 0.123</span> moles of OH- in solution.
so to prevent the precipitation of mg(oh)2
0.123 - 0.058 = 0.065 Molar NH4+ is needed
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Explanation:
Hardness of rocks makes weathering difficult and not easy to come by.
Weathering is the physical disintegration and chemical decomposition of rocks to form sediment and soils.
The agents of weathering are primarily the agents of denudation which are wind, rainfall, glacier, gravity and temperature.
- Most igneous and metamorphic rocks are usually termed hard rocks.
- Sedimentary rocks typically falls into the category of soft rocks.
- Hard rocks are more compact and have their crystals woven into one another.
- It takes a longer time for them to get weathered.
- Soft rocks are often times bounded by cements.
- The cements are chemical substances that easily reacts and can cause they to be easily broken down.
Therefore, the harder a rock is, the more time it takes for it to be disintegrated.
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Explanation:
IF YOU BURNED THE PAPER THERE WILL BE ONLY ASHES
The formula of aluminum sulfate is Al₂(SO₄)₃
Hence, 1 mole of Al₂(SO₄)₃ has 2 moles of Al, 3 moles of S and (4 x 3) or 12 moles of O
9 moles of Al₂(SO₄)₃ x (2 moles of Al/1 mole of Al₂(SO₄)₃) = 18 moles of Al
9 moles of Al₂(SO₄)₃ x (3 moles of S/1 mole of Al₂(SO₄)₃) = 27 moles of S
9 moles of Al₂(SO₄)₃ x (12 moles of O/1 mole of Al₂(SO₄)₃) = 108 moles of O
The number of moles of Al, S, and O atoms are 18, 27 and 108.
Is the water line of boat when someone boards or leaves it.
