Answer:
Explanation:
Since salt is composed of two ions Na+ and Cl- it will attract to the opposite poles of the water and form a ion-dipole bond. This will cause the phenomenon freezing point depression where as the name states it will take a lower tempertature to freeze it. So instead of freezing at 0 degrees c it will freeze at a negative 2 or so on.
The half life equation is -->P(t) = Pi (0.5) ^ (t/c)
c is equal to the element to reach its half-life (5 seconds)t is equal to the duration of time the element is expose to (20 seconds)Pi is the initial amount (340)0.5 is the base of this exponential function to represent half-life.P(t) is the expression for the function of time
P(20) = 340 (0.5)^20/5P(20) = 340 (0.5) ^4P(20)= 21.25 grams
Fraction = P(t)/Pi = P(20)/Pi =21.25/340 =1/16
Therefore, when given 20 seconds, 340 grams of Fluorine-21 will degrade to 21.25 grams OR 1/16 of its original mass.
Hope this method helps! (This is my answer btw, I think you may have accidentally posted twice?)
You determine the correct number of significant figure of a measurement in a graduated cylinder by looking at the smallest division on the graduated cylinder. If the division is divided up to the ones place, you can still read the half of that division or the .50 measurement. So, you can have until the tenths place in your measurement.
<h3>
Answer:</h3>
132.03 g
<h3>
Explanation:</h3>
<u>We are given;</u>
- The equation for the reaction as;
Fe₂O₃ + 3CO → 2Fe + 3CO₂
- Molar masses of CO and CO₂ as 28.01 g/mol and 44.01 g/mol respectively
- Mass of CO as 84 grams
We are required to calculate the mass of CO₂ that will produced.
<h3>Step 1: Calculate the number of moles of CO</h3>
Moles = Mass ÷ Molar mass
Molar mass of CO = 28.01 g/mol
Therefore;
Moles of CO = 84 g ÷ 28.01 g/mol
= 2.9989 moles
= 3.0 moles
<h3>Step 2: Calculate the number of moles of CO₂</h3>
- From the reaction, 3 moles of CO reacts to produce 3 moles of CO₂
- Therefore; the mole ratio of CO to CO₂ is 1 : 1
- Hence; Moles of CO = Moles of CO₂
Moles of CO₂ = 3.0 Moles
But; mass = Moles × molar mass
Thus, mass of CO₂ = 3.0 moles × 44.01 g/mol
= 132.03 g
Hence, the mass of CO₂ produced from the reaction is 132.03 g
Answer:
The interaction reaction of calcium oxide and water leads to the formation of calcium hydroxide, this reaction is exothermic, which indicates that energy is released.
CaO(s) + H2O ⇒ Ca(OH)2
Explanation:
Calcium oxide reacts violently with water, causing it to reach 90 C. It then forms calcium hydroxide, also called slaked lime. It is heated because it releases energy in the form of heat, because the new substance formed (slaked lime) has less internal energy than the original and this is released in the form of heat. As a general rule, acid and base solutions are exothermic.
