The purpose of an universal indicator is to test wether a solution is acid or if its a base. It changes colors according to the PH's. It helps a lot in the indication of a chemical reaction because it can say if <span>each component loses or gains protons depending upon the acidity or basicity of the solution being tested.An universal indicator can say if a determined solution proves to be endothermic or exothermic. If the solution is not tested as acid or base then we cannot knwo if there will be an endothermic reaction or an exhotermic one</span>
Answer:
that is the answer
Explanation:
the atoms in each side of the equation must be equal.
Answer:
Oxygen
Explanation:
Oxygen has 6 valence electrons and it wants to have 8 to obtain a stable octet. So Oxygen gains two electrons in the bond, developing an anion.
It is also a non-metal, and they tend to gain anions.
Lattice energy of potassium nitrate (KNO3) = -163.8 kcal/mol
Hydration energy of KNO3 = -155.5 kcal/mole
Heat of solution is the amount of heat absorbed by water when 1 mole of KNO3 is dissolved in it
Heat of solution = Hydration energy - Lattice energy
= -155.5 -(-163.8) = 8.3 kcal/mol
1 kcal/mol = 4.184 kJ/mole
Therefore, 8.3 kcal/mole = 4.184 * 8.3 = 34.73 kJ/mol
Now, 34.73 kJ of heat is absorbed when 1 mole of KNO3 is dissolved
The given 105 kJ of heat would correspond to : 105/34.73 = 3.023 moles of KNO3
Molar mass of KNO3 = 101.1 g/mole
Mass of KNO3 = Molar mass * moles
= 101.1 * 3.023 = 305.63 g = 0.3056 kg
Answer:
1.8 × 10⁻⁴ mol M/s
Explanation:
Step 1: Write the balanced reaction
2 Br⁻ ⇒ Br₂
Step 2: Establish the appropriate molar ratio
The molar ratio of Br⁻ to Br₂ is 2:1.
Step 3: Calculate the rate of appearance of Br₂
The rate of disappearance of Br⁻ at some moment in time was determined to be 3.5 × 10⁻⁴ M/s. The rate of appearance of Br₂ is:
3.5 × 10⁻⁴ mol Br⁻/L.s × (1 mol Br₂/2 mol Br⁻) = 1.8 × 10⁻⁴ mol Br₂/L.s
