Acidic and basic are two extremes that describe chemicals, just like hot and cold are two extremes that describe temperature. Mixing acids and bases can cancel out their extreme effects, much like mixing hot and cold water can even out the water temperature. A substance that is neither acidic nor basic is neutral.
The character of acidic, basic and neutral is defined by the concentration of hydrogen ions [H+](mol/L). A solution with a concentration of hydrogen ions higher than 10-7mol/L is acidic, and a solution with a lower concentration is alkaline (another way to say basic). Using the formula, pH=-log[H+], a pH of 7 is neutral, a pH less than 7 is acidic, and a pH greater than 7 is basic. As one can see from this formula, ten times a given concentration of hydrogen ions means one unit lower in terms of pH value (higher acidity), and vice versa.
The formula for ph is given by:pH=−log10[H+]
What is the concentration of H+ ions at a pH = 8?
In calculating for the concentration of hydrogen ion, the formula is given by:[H+]=(10)^(-pH)
Solution:
[H+]=(10)^(-8)[H+]=0.00000001 mol/L
What is the concentration of OH– ions at a pH = 8?pH+pOH=148+pOH=14pOH=6
[OH-]=(10)^(-pOH)[OH-]=(10)^(-6)[OH-]=0.000001
What is the ratio of H+ ions to OH– ions at a pH = 2?The ratio is 0.00000001:0.000001 which is equal to 0.01
Answer:
Explanation:
Given that:
Pressure = 791 mmHg
Temperature = 20.0°C
The conversion of T( °C) to T(K) is shown below:
T(K) = T( °C) + 273.15
So,
T = (20 + 273.15) K = 293.15 K
T = 293.15 K
Volume = 100 L
Using ideal gas equation as:
PV=nRT
where,
P is the pressure
V is the volume
n is the number of moles
T is the temperature
R is Gas constant having value = 62.3637 L.mmHg/K.mol
Applying the equation as:
791 mmHg × 1.14 L = n × 62.3637 L.mmHg/K.mol × 293.15 K
⇒n of
produced = 0.0493 moles
According to the reaction:-

1 mole of carbon dioxide is produced 1 mole of calcium carbonate reacts
0.0493 mole of carbon dioxide is produced 0.0493 mole of calcium carbonate reacts
Moles of calcium carbonate reacted = 0.0493 moles
Molar mass of
= 100.0869 g/mol
The formula for the calculation of moles is shown below:
Thus,

Impure sample mass = 5.28 g
Percent mass is percentage by the mass of the compound present in the sample.
Answer:
hecto-
Explanation:
The prefix value of 100 is hecto therefore 100X can be called hecto-x.
Such prefixes as this are expressed in the order of tens. Units generally exists scientifically in multiples and submultiples form using prefixes.
For the multiples:
10 deca(da)
100 hecto(h)
1000 kilo(k)
1000000 mega(M)
1000000000 giga(G)