Answer is: a) in the presence of a base.
Phenolphthalein is colorless in acidic solutions and pink in basic solutions.
Acid-base indicators are usually weak acids or bases and they are chemical detectors for hydrogen or hydronium cations.
Example for acid-base indicator is phenolphthalein (molecular formula C₂₀H₁₄O₄).
When solution turns phenolphthalein pink, it means it is basic (pH>7).
Correct answer is magnesium bromide. This is an ionic compound with metal forming a positive ion - K+ and halogen forming a negative ion - Br-. When group 7 element form ions they have a suffix -ide. Bromine is the element and when it forms a negative ion bromine is called bromide with the suffix.
Magnesium gives 2 electrons and bromine can take only 1 electron, therefore 2 bromine atoms are needed. Therefore magnesium forms ionic bonds with 2 bromine atoms.
The compound is called magnesium bromide
Answer:
D
Explanation:
It would definitely affect size because breeding will change that trait
Answer:
Option B will require a shorter wave length of light.
Explanation:
The bonding between Ozone (O3) and Oxygen (O2) can be used to explain why the breaking of oxygen into Oxygen radicals will require a shorter wave length.
- The bond between Oxygen (O2) is a double bond while Ozone (O3) has an intermediate bond between a double bond and a single bond.
- The bond order of Oxygen (O2) is equals 2 while that of Ozone (O3) is 1.5. Since the bond order of oxygen is higher, it will require more energy to break the bond compared to breaking the Ozone (O3) bond.
- Recall that Energy is inversely proportional to wave length.
- So it will require a shorter wave length to break the Oxygen (O2) into its radicals.
Answer:

Explanation:
Hello,
In this case, the enthalpy of combustion is understood as the energy released when one mole of fuel, in this case octene, is burned in the presence of oxygen and is computed with the enthalpies of formation of the fuel, carbon dioxide and water as shown below (oxygen is circumvented as it is a pure element):

Thus, since we already know the enthalpy of combustion of the fuel, for carbon and water we have -393.5 and -241.8 kJ/mol respectively, thereby, the enthalpy of combustion turns out:

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