Before 7 after 9. A pH smaller than 7 indicates acidity with 0 being completely acidic. A pH greater than 7 shows alkalinity with 14 being completely alkaline. 7 is neutral. Since NaOH is alkaline, adding it to a neutral substance would increase the pH and it would increase from 7 to 9.
A fuse melts to protect a circuit.
Answer:
1. An increase in the core temperature
2. A decrease in the core radius.
Explanation:
The sun is a Main Sequence star. A Main Sequence star is powered by fusing hydrogen into Helium within its core.
For this fusion to take place, a temperature of at least 10 million Kelvin is required, beyond this point, the fusion rate is directly related to the core temperature. If the temperature increases, the fusion rate will greatly increase.
Something similar happens if the core reduces its radius. This can happen at the end of the star's lifetime, shortly before it becomes a red giant. Once the hydrogen is depleted, the core will start to shrink because the force of gravity, and as it gets smaller, gets more compressed, and its temperature increases. The outer layers of remaining Hydrogen that were outside the core now begin to heat up, and as the core continues to shrink, the star gets hot enough to begin the fusion process again, and the fusion rate can even be higher than it was during the first phase of the star, as the star becomes a Red Giant.
Answer:
16.82 kJ/g
Explanation:
The Heat energy generated by the pentance combusion caused the temperature increasing of the caloriemeter and the water inside it.
Heat energy of a substace can be calculated using
Q = mcθ
C= mc
where Q = Heat energy
m =mass
c = specific heat capacity
C = heat capacity
θ =temperature difference
(Temperature difference = final temperature - initial temperature.)
heat absorbed by water = mcθ
= 1 * 4.184 * (22.82-20.22)
= 10.88 J --------------(1)
heat absorbed by calorimeter = Cθ
= 2210 *(22.82-20.22)
= 5746 J ---------------(2)
Combustion energy = heat absorbed by water + heat absorbed by calorimeter
Combustion energy = 10.88+ 5746 = 5756.88 J
= 5.757 kJ
heat of combustion of pentane = Combustion energy / mass
= 5.757 / 0.3423
= 16.82 kJ/g
Sukarno was succeeded by Suharto. So choice ' C ' is false.
