Given parameters:
Mass of H₃PO₄ = 49g
Unknown:
Number of moles = ?
Solution:
To find the number of moles of a given specie;
number of moles =
Molar mass = 3(1) + 31 + 4(16) = 98g/mol
Input the parameters and solve;
Number of moles = = 0.5mole
The number of moles is 0.5mole
Answer:
We are given:
Volume (V) = 0.25 L
Pressure (P) = 0.93 atm
Temperature (T) = 15.4°C OR 288.4 K
<u>Solving for the number of moles of CO₂:</u>
From the ideal gas equation:
PV = nRT
replacing the variables
0.93 * 0.25 = n (0.082)(288.4)
n = 0.00983 moles
<u>Number of molecules:</u>
Number of moles= 0.00983
number of molecules in 1 mole = 6.022 * 10²³
Number of molecules in 0.00983 moles = 0.00983 * 6.022 * 10²³
Number of molecules = 5.91 * 10²¹
Answer:
Pb(NO₃)₂ + K₂CrO₄ ⟶ PbCrO₄ + 2KNO₃
Step-by-step explanation:
The unbalanced equation is
Pb(NO₃)₂ + K₂CrO₄ ⟶ PbCrO₄ + KNO₃
Notice that the complex groups like NO₃ and CrO₄ stay the same on each side of the equation.
One way to simplify the balancing is to replace them with a single letter.
(a) For example, let <em>X = NO₃</em> and <em>Y =CrO₄</em>. Then, the equation becomes
PbX₂ + K₂Y ⟶ PbY + KX
(b) You need 2X on the right, so put a 2 in front of KX.
PbX₂ + K₂Y ⟶ PbY + 2KX
(c) Everything is balanced. Now, replace X and Y with their original meanings. The balanced equation is
Pb(NO₃)₂ + K₂CrO₄ ⟶ PbCrO₄ + 2KNO₃
This is because most ionic compounds consist of a bond between a metal and a non-metal and if the compound was in solid state it tends to be brittle because of the metal part of the compound