95 percent of species known are invertebrates
Answer:
HCl solution - H30+ and Cl ions. pH 3
NaCl - Na+ and Cl-. pH 7
Explanation:
a) HCl solution - the hydrogen ion combines with water molecule to form the hydronium molecule which is responsible for acidity. The chloride ion is also found in solution.
pH = -log [H+] = -log(10^-3) = 3
b) NaCl 10-3 g. The solid dissocates in water forming the Na+ and Cl- ions. None of these ions affect pH
Air is mainly composed of N2 (78%), O2 (21%) and other trace gases. Now, the total pressure of air is the sum of the partial pressures of the constituent gases. The partial pressure of each gas, for example say O2, can be expressed as:
p(O2) = mole fraction of O2 * P(total, air) ----(1)
Thus, the partial pressure is directly proportional to the total pressure. If we consider a sealed container then, as the temperature of air increases so will its pressure. Based on equation (1) an increase in the pressure of air should also increase the partial pressure of oxygen.
Answer:
836.8J
Explanation:
Heat energy = ?
Mass = 100g
Initial temperature (T1) = 21°C
Final temperature (T2) = 23°C
Specific heat capacity of water (c) = 4.184J/g°C
To solve this question, we'll need to use the formula for calculating heat energy of a substance.
Q = mc∇t
Q = heat energy of substance
M = mass of substance
C = specific heat capacity of substance
∇t = change in temperature = T2 - T1
Q = 100 × 4.184 × (23 -21)
Q = 418.4 × 2
Q = 836.8J
The heat energy required to raise 100g of water from 21°C to 23°C is 836.8J
