Answer:
D.) The nuclear model describes the atom as a dense, positive nucleus surrounded by a cloud of negative electrons.
1) we can calculate the molecular weight of H₃PO₄
atomic mass (H)=1 amu
atomic mass (P)=31 amu
atomic mass (O)=16 amu
molecular weight (H₃PO₄)=3(1)+31+4(16)=98 amu.
1 mol (H₃PO₄)=98 g
1 mol= 6.022 * 10²³ molecules.
2) we calculate the mass of 4.00*10²³ molecules.
98 g-------------------6.022*10²³ molecules
x------------------------4.00*10²³ molecules
x=(98 g * 4.00*10²³ molecules) / 6.022*10²³ molecules≈65 g
Answer: 65 g
Answer:
The final volume of the gas is 36.1 L.
Explanation:
Given:
Initial pressure of the gas is, 
Final pressure of the gas is, 
Initial volume of the gas is, 
Final volume of the gas is, 
Here, we shall use Boyle's Law which states that for a process under constant temperature, the pressure of the gas changes inversely with the change in volume.
Here, the pressure is increased. So, the volume of the gas is decreased.
Therefore, as per Boyle's Law:
So, the final volume of the gas is 36.1 L.
Answer:
The heat released by the combustion is 20,47 kJ
Explanation:
Bomb calorimeter is an instrument used to measure the heat of a reaction. The formula is:
Q = C×m×ΔT + Cc×ΔT
Where:
Q is the heat released
C is specific heat of water (4,186kJ/kg°C)
m is mass of water (1,00kg)
ΔT is temperature change (23,65°C - 20,45°C)
And Cc is heat capacity of the calorimeter (2,21kJ/°C)
Replacing these values the heat released by the combustion is:
<em>Q = 20,47 kJ</em>
