C.
Anthracite has the highest carbon compact and fewest impurities.
Also, the highest calorific of all types of coal except for graphite.
Answer:
So, Luke and Sian has to increase the pH of the soil by adding base to it.
Explanation:
The pH is defined as the negative logarithm of the hydrogen ion concentration in their aqueous solution.
![pH=-\log[H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BH%5E%2B%5D)
- With increase in hydrogen ion concentration the pH value decreases.
- With decrease in hydrogen ion concentration the pH value increases.
The pH of the soil after testing it on a kit comes out be 5.0, but they both need pH of the soil to 6.5.
Comparison of pH of soil:
= 5.0 < 6.5
= High hydrogen ion concentration > High hydrogen ion concentration
So, Luke and Sian has to increase the pH of the soil by adding base .Doing so will decrease the hydrogen ion concentration in the soil (where as addition of acid lower the pH of soil).
C because
Explanation Plato
Use Charles' Law: V1/T1 = V2/T2. We assume the pressure and mass of the helium is constant. The units for temperature must be in Kelvin to use this equation (x °C = x + 273.15 K).
We want to solve for the new volume after the temperature is increased from 25 °C (298.15 K) to 55 °C (328.15 K). Since the volume and temperature of a gas at a constant pressure are directly proportional to each other, we should expect the new volume of the balloon to be greater than the initial 45 L.
Rearranging Charles' Law to solve for V2, we get V2 = V1T2/T1.
(45 L)(328.15 K)/(298.15 K) = 49.5 ≈ 50 L (if we're considering sig figs).