Answer:
Explanation:
Fe⁺² (aq) + 2e⁻ = Fe (s) ; E⁰ = - .44 V
Fe⁺³ (aq) + e⁻ = ® Fe²⁺ (aq) ; E⁰ = + .77 V
Reduction potential of second reaction is more , so it will take place , ie Fe⁺³ will be reduced and Fe will be oxidised .
So reaction in the combined cell will be
2Fe⁺³ + Fe = 3Fe⁺²
cell potential = .77 - ( - .44 )
= 1.21 V .
Answer:

Explanation:
Given:
Initial volume of the balloon V1 = 348 mL
Initial temperature of the balloon T1 = 255C
Final volume of the balloon V2 = 322 mL
Final temperature of the balloon T2 =
To calculate T1 in kelvin
T1= 25+273=298K
Based on Charles law, which states that the volume of a given mass of a ideal gas is directly proportional to the temperature provided that the pressure is constant. It can be applied using the below formula

T2=( V2*T1)/V1
T2=(322*298)/348

Hence, the temperature of the freezer is 276 K
The sample is likely to be from a meteorite.
The reason for this is the fact that the isotope Copper-63 is more abundant on planet Earth than the isotope Copper-65 is. Therefore, if a sample of rock has Cu-65 in a greater quantity, it is likely to be from outer space. Many other elements entered the Earth's crust as a result of meteorite impacts, such as Iron (Fe).
Answer:
0.467 kilograms of protein or carbohydrates
Explanation:
First, there is a need to understand that <em>1 kJ = 0.239 kCal</em>
Hence, 17 kJ = 17 x 0.239 = 4.063 kCal
The race requires 650.0 kCal/hr and has to last for 175 minutes.
175 minutes = 175/60 = 2.917 hrs
The total kCal requires for the race = 650 x 2.917 = 1,895.833 kCal
1 g of protein or carbohydrate food produces 17.0 kJ or 4.063 kCal of energy. Hence, the total g of protein or carbohydrate that will produce 1,895.833 kCal of energy would be;
1,895.833/4.063 = 466.609 g
<em>1 g = 0.001 kg</em>
466.609 g = 466.609 x 0.001 = 0.467 kg
<em>Hence, </em><em>0.467 </em><em>kilograms of proteins or carbohydrates must be consumed.</em>
The k is the proportionality constant of the reaction. Graphically, this is the slope of the graph. Since the graph is linear, then there is only 1 value of k. To calculate this, choose two random points in the line. Suppose we use (0.15,10) and (0.30,20), calculate for the slope.
Slope = k = (10 - 20)/(0.15 - 0.30) = 66.67 mL CO₂/g CaCO₃