Answers:
1. 7500 J; 3800 J/g
Step-by-step explanation:
1. Joules gained by water
q = mcΔT
Data:
m = 100 g
C = 4.184 J·°C⁻¹g⁻¹
ΔT = 18 °C
Calculation:
q = 100 × 4.184 × 18 =7500 J
2. Joules per gram of Pringle
Energy gained by water = energy lost by Pringle
q = -mΔH
7500 J = -1.984 g × ΔH
ΔH = -7500 J/1.984 g = -3800 J/g
Pringles contain 3800 J of food energy per gram.
Answer:
P₂ = 299.11 KPa
Explanation:
Given data:
Initial volume = 600 mL
Initial pressure = 70.00 KPa
Initial temperature = 20 °C (20 +273 = 293 K)
Final temperature = 40°C (40+273 = 313 K)
Final volume = 150.0 mL
Final pressure = ?
Formula:
P₁V₁/T₁ = P₂V₂/T₂
P₁ = Initial pressure
V₁ = Initial volume
T₁ = Initial temperature
P₂ = Final pressure
V₂ = Final volume
T₂ = Final temperature
Solution:
P₂ = P₁V₁ T₂/ T₁ V₂
P₂ = 70 KPa × 600 mL × 313 K / 293K ×150 mL
P₂ = 13146000 KPa .mL. K /43950 K.mL
P₂ = 299.11 KPa
The balanced equation for the reaction between Ba(OH)₂ and HCl is ;
Ba(OH)₂ + 2HCl ----> BaCl₂ + 2H₂O
When equal volumes of both acid and base are added, the pH is 7 which means its neutral.
This means that the H⁺ ions and OH⁻ are equal and they have neutralised each other. All the ions have reacted to form water molecules.
Dissociation of base and acid are as follows;
Ba(OH)₂ ---> Ba²⁺ + 2OH⁻
1 mol of Ba(OH)₂ dissociates to 2 mol H⁺
HCl ---> H⁺ + Cl⁻
n moles of HCl give out n mol of H⁺ ions
H⁺ = OH⁻ which is why solution is neutral
then OH⁻ moles present are n mol
then Ba(OH)₂ moles present should be n/2 mol
molarity of HCl = 0.5 mol/L
since volumes are equal number of moles are directly proportional to molarity
molarity of Ba(OH)₂ = 0.5/2 = 0.25 M
Answer:
<h2>0.059 moles</h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
We have the final answer as
<h3>0.059 moles</h3>
Hope this helps you
