The experiment involving the determination of the number of ice cubes required to keep the temperature of the glass under 15 degrees Celcius, the following things have to be kept in mid:
- The<u> temperature</u> of the surroundings
- The initial temperature of the <u>glass</u>
- The <u>number of ice cubes </u>added to the water in the glass
In order to keep into consideration the changing environmental temperatures (which is a variable in the experiment), the experiment had to be conducted daily to get <u><em>accurate results </em></u>keeping into consideration all the factors.
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<u>Answer:</u> The concentration of the solution is 0.25 M
<u>Explanation:</u>
Let the volume of solution of 2.5 M NaCl be 10 mL
We are given:
Dilution ratio = 1 : 10
So, the solution prepared will have a volume of = 
To calculate the molarity of the diluted solution, we use the equation:
where,
are the molarity and volume of the concentrated NaCl solution
are the molarity and volume of diluted NaCl solution
We are given:
Putting values in above equation, we get:

Hence, the concentration of the solution is 0.25 M
Answer:
decreased by a factor of 10
Explanation:
pH is defined in such a way that;
pH= −log10(H)
Where H represents the concentration of Hydronium or Hydrogen ions
Given that pH is changed from 1 to 2,
By rearranging the above formula , we get 10−pH = H
- if pH=1,H=10−1=0.1M
- if pH=2,H=10−2=0.01M
Therefore, 0.1/0.01 = 10 and 0.1 > 0.01
Hence, the concentration of hydronium ions in the solution is decreased by a factor of 10
The answer is (4) 4. Germanium is a main group element in group 4A. Therefore, like carbon, it has 4 valence electrons in the ground state.
Actually, that does not happen until the protostar becomes a star when nuclear ignition starts and is maintained. It takes awhile for new star to go through its T-Tauri stage and settle down on the main sequence.
<span>A STAR does not reach hydrostatic equilibrium until it on the main sequence. Otherwise, it would remain a brown dwarf with not enough mass to to maintain nuclear fusion for more than 3,000 to 10,00 years. </span>