Just divide the two (2 / 0.05) and you will get your answer; there are 40 drops of bloodin the collection tube.
1) Endothermic
2) Heat absorbed by reaction = 2511.6J
3)ΔH_rxn = 18.2 kJ/ mol
Explanation:
Mass of KCl = 10.3 g
Moles of KCl = mass of KCl / molar mass of KCl
= 10.3 g / 74.5513 g/mol
=0.138 mol
Mass of water, m = 200 g
Specific heat of water, C= 4.186 Jg^-1°C^-1
T_initial = 22.0C
T_final = 19.0°C
ΔT = T_final - T_initial
=19.0°C - 22.0°C
= -3.0°C
Heat absorbed = Heat released
q_rxn =-q_water
so,
q_water = m CΔT
substitute
q_water = 200g * 4.186J g^-1 °C^-1 *(-3.0°C)
= -2511.6J
Heat absorbed by reaction = 2511.6J
q_rxn = -q_water = 2511.6J
ΔH_rxn = q_rxn /moles of KCl
=2511.6J / 0.138 mol
ΔH_rxn =18.2kJ / mol
The reaction is a endothermic reaction.
Answer:
[H₃O⁺] = 2.5 × 10⁻¹⁰ M
pH = 9.6
Explanation:
Step 1: Given data
Concentration of OH⁻ in the solution ([OH⁻]): 4.0 × 10⁻⁵ M
Step 2: Calculate the concentration of H₃O⁺ in the solution
Let's consider the self-ionization of water.
2 H₂O(l) ⇄ H₃O⁺(aq) + OH⁻(aq)
The <em>ion-product of water (Kw)</em> is:
<em>Kw = 1.0 × 10⁻¹⁴ = [H₃O⁺] × [OH⁻]</em>
[H₃O⁺] = 1.0 × 10⁻¹⁴/[OH⁻]
[H₃O⁺] = 1.0 × 10⁻¹⁴/4.0 × 10⁻⁵
[H₃O⁺] = 2.5 × 10⁻¹⁰ M
Step 3: Calculate the pH of the solution
We will use the following expression.
<em>pH = -log [H₃O⁺]</em>
pH = -log 2.5 × 10⁻¹⁰
pH = 9.6
An endothermic reaction is the opposite. This is when a reaction starts colder and ends up hotter, taking in energy from start to finish. In an endothermic reaction, the system gains heat as the surroundings cool down. In an exothermic reaction, the system loses heat as the surroundings heat up.
The correct choices are: (2) the particles in the Warner cup has more kinetic energy and (3) if there are two different amounts of the same liquid the temp is a good way to compare thermal energies