b) in the presence of an acid
c) when it is in a neutral solution
d) when it is reacting with a metal
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).
Phenolphthalein turns pink in the presence of a base.
Phenolphthalein turns pink in the presence of a base. It is a pH indicator that changes color depending on the acidity or alkalinity of a solution. In an acidic solution, phenolphthalein remains colorless, while in a basic solution, it turns pink.
#SPJ6
iron? (8 points)
Answer:
first change cm to m and g to kg so you will find the volume first which is 0.02 by 0.03 by 0.02 your answer is 0.000012 m . using the formula density=mass/volume take 0.094/ 0.00012 then divide
Explanation:
All the elements of group 1 in the periodic table are known as alkali metals. These are lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (fr).
Characteristics of alkali metals are as follows.
1200 meters
B.
2400 meters
C.
3600 meters
D.
4800 meters
E.
7200 meters
B) it is a product in one intermediate reaction and a catalyst in the other reaction.
C) it is a reactant in one intermediate reaction and a product in the other reaction.
D) it is a reactant in both of the intermediate reactions.
Answer: Option (C) is the correct option.
Explanation:
When two intermediate chemical equations are combined, the same substance that appears in the same phase can be canceled out, provided that it is a reactant in one intermediate reaction and a product in the other reaction.
For example,
....(1)
.........(2)
Cancelling the common species in both the equations as follows.
Therefore, on addition we get the equation as follows.
A yield of NH3 of approximately 98% can be obtained at 200°C and 1,000 atmospheres of pressure.
How many grams of Ny must react to form 1.7 grams of ammonia, NH3?
0.052 g
1.49
0.00589
2.8 g
Answer:
Explanation:
Here we have to use stoichiometry.
First of all, we have to calculate the mass of 100% of yield:
1.7 g ------- 98%
X -------- 100%
X = 1.73 g (approximately)
Second, we have to calculate the mass of N2 that is necessary to react to produce the mass of 1.73g of NH3. To do that, we have to use the Molar mass of N2 and NH3 and don't forget the stoichiometric relationship between them.
Molar Mass N2 : 14x2 = 28 g/mol
Molar Mass NH3: 14 + 3 = 17 g/mol
28g (N2) ------- 17x2 (NH3)
X ------------ 1.73 g
X = 1.42 g (approximately)