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).
Answer :
The steps involved in the electron dot structure of 
are :
First we have to determine the total number of valence electron in .
Number of valence electrons in N = 5
The charge on N is (-3). So, we add 3 electrons.
Total number of valence electrons = 5 + 3 = 8 electrons
The image is shown below.
False-- most of the time not enough energy is put into the system, so the compounds or whatever cant break down fully into their elements
Answer:
find the number of moles of solute dissolved in solution
,
find the volume of solution in liters,
then divide moles solute by liters solution
Explanation:
<h3>
Answer:</h3>
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
<h3>
Explanation:</h3>
- The equation for the reaction shown represents the combustion of ethane.
C₂H₆ + O₂ → CO₂ + H₂O
- To balance the equation we put the coefficients, 2, 7, 4, and 6 on the reactants and products.
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
- Balancing chemical equations makes the number of atoms of each element equal on both side of the equation.
- It ensures that chemical equations obey the law of conservation of mass in chemical reactions.
