Answer:A) It was developed from past observations- true
It is subject to experimentation and revision.- false
It explains why mass is conserved- false
It predicts future observations-true
Explanation:
Before a hypothesis is proclaimed to be a law in science, numerous observation must have confirmed its validity and rigorous experimentation under carefully controlled conditions usually precedes the acceptance of a hypothesis as a law. The law of conservation of mass was developed from numerous past observation that proved its validity.
Answer:
13.20
Explanation:
Step 1: Calculate the moles of Ba(OH)₂
The molar mass of Ba(OH)₂ is 171.34 g/mol.
0.797 g × 1 mol/171.34 g = 4.65 × 10⁻³ mol
Step 2: Calculate the molar concentration of Ba(OH)₂
Molarity is equal to the moles of solute divided by the liters of solution.
[Ba(OH)₂] = 4.65 × 10⁻³ mol/60 × 10⁻³ L = 0.078 M
Step 3: Calculate [OH⁻]
Ba(OH)₂ is a strong base according to the following equation.
Ba(OH)₂ ⇒ Ba²⁺ + 2 OH⁻
The concentration of OH⁻ is 2/1 × 0.078 M = 0.16 M
Step 4: Calculate the pOH
pOH = -log OH⁻ = -log 0.16 = 0.80
Step 5: Calculate the pH
We will use the following expression.
pH + pOH = 14
pH = 14 - 0.80 = 13.20
Answer:
1.0 mole
Explanation:
From the question given above, the following data were obtained:
Volume (V) = 5 L
Temperature (T) = 205 K
Pressure (P) = 340 KPa
Gas constant (R) = 8.31 KPa.L/Kmol
Number of mole (n) =?
Using the ideal gas equation, the number of mole of the gas in the container can be obtained as follow:
PV = nRT
340 × 5 = n × 8.31 × 205
1700 = n × 1703.55
Divide both side by 1703.55
n = 1700 / 1703.55
n = 1.0 mole
Thus, the number of mole of the gas in the container is 1.0 mole
Answer:
H2-1
H2+-1/2
H22- zero
Explanation:
Bond order= Bonding electrons-antibonding electrons/2
In H2, there are two bonding electrons and no antibonding electrons. In H2+ there is only one bonding electron and no antibonding electron while in H22- there are two bonding and two antibonding electrons respectively.
Answer:
3.8moles
Explanation:
The molar mass of Lithium = 7g/mol
Mass conc. of lithium = 26.4g
Number of mole = Mass conc/Molar Mass
Number of mole = 26.4/7 = 3.8moles
