Here is an acid-base reaction. Hydrochloric acid (HCl) reacts with strontium hydroxide [ Sr(OH)2 ]
Ions H+ and OH- neutralize each other. If the amounts are not equal, one of them will be in excess.
Follow the steps as
1. Find moles of ions: mole= Molarity * Volume (in liter) ; n= M * V OR millimole = Molarity * Volume (in ml) ;
2. Write the equation
3. Find out excess ion
4. Use final volume (V acid + V base ) to calculate concentration of excess ion.
n HCI = 28 ml * 0.10 M = 0.28 mmol, releases 0.28 mmol H+ ions
n Sr(OH)2= 60 ml * 0.10 M= 0.60 mmol, releases 2* 0.60=1.20 mmol OH- ions
since Sr(OH)2⇒ Sr2+ + 2OH-
Neutralization reaction is OH- + H+ ---> H2O. The ratio is 1:1. That means 1 mmol hydroxide ions will neutralize 1 mmol hydrogen ions. Since OH- ions are greater in amount, they will be in excess
n(OH-) - n(H+)= 1.20 - 0.28 = 0.92 mmol OH- ions UNREACTED.
Total volume= V acid + V base= 28 ml + 60 ml = 98 ml
Molarity of OH- ions= mole / Vtotal = 0.92/98= 0.009 M
The answer is 0.009 M.
Answer:
A
Explanation:
Iron has the ground state electronic configuration [Ar]3d64s2
Fe2+ has the electronic configuration [Ar]3d6.
In an octahedral crystal field, there are two sets of degenerate orbitals; the lower lying three t2g orbitals, and the higher level two degenerate eg orbitals. Strong field ligands cause high octahedral crystal field splitting, there by separating the two sets of degenerate orbitals by a tremendous amount of energy. This energy is much greater than the pairing energy required to pair the six electrons in three degenerate orbitals. Since CN- is a strong field ligand, it leads to pairing of six electrons in three degenerate orbitals
Since f=ma assuming you knew the mass of the marble and the total amount of force acting on it than you would divide the amount of force by the mass.
Answer: option <span>C. the total energy inside the calorimeter will decrease.
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Justification:
The answer is a direct application of the first law of thermodynamic (the law of conservation of energy).
By telling that the t<span>he calorimeter is sealed so that there is no heat exchanged between the contents of the container and the surrounding air, the first law of thermodynamics implies that the total energy inside the calorimeter will not change.
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<span>That statement, without adding any more is enough justification.
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Regarding, the other statements, you can show they are true:
<span>A.
the thermometer will show an increase in temperature.
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</span><span>Since the reaction is exothermic, the heat released will increase the temperature inside the sealed calorimeter,which, of course, is shown by the termometer.
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</span><span>B. The potential
energy of the products will be lower than that of the reactants.
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</span><span>In any exothermic reaction, the potential energy of the products is lower than that of the reactants, because the heat released is lost by the reactants when they react and transform into the products.
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</span><span>D. The water
increases in temperature as the reaction gives off heat</span>.
Sure. The heat cannot leave the sealed calorimeter, but the water inside the calorimeter will absorb that heat: the molecules of water will gain kinetic energy and so its temperature will be increase.
