Answer:
They are made up of electrons, neutrons and protons
Explanation:
<span>Avogadro's number.
1 mole of any substance, molecule or element is equal to a certain amount of atom.
6.022 x 10^23 is the Avogradro's constant.
Magnesium Oxide is a compound. therefore if you have 30.3 g of it (1 mol), it will have the same number of atoms.
34.69 moles of MgO has 208.9 x 10^23 number of atoms.
2.089 x 10^25 is also a correct answer.</span><span>
</span>
Answer:
oxygen is limiting reactant
Explanation:
Given data:
Mass of hydrogen = 16.7 g
Mass of oxygen = 15.4 g
Limiting reactant = ?
Solution:
Chemical equation:
2H₂ + O₂ → 2H₂O
Number of moles of hydrogen:
Number of moles = mass/ molar mass
Number of moles = 16.7 g/ 2 g/mol
Number of moles = 8.35 mol
Number of moles of oxygen:
Number of moles = mass/ molar mass
Number of moles = 15.4 g/ 32 g/mol
Number of moles = 0.48 mol
Now we will compare the moles of both reactant with product,
H₂ : H₂O
2 : 2
8.35 : 8.35
O₂ : H₂O
1 : 2
0.48 : 2×0.48 = 0.96 mol
The number of moles of water produced by oxygen are less so it will limiting reactant.
Answer:
Their average kinetic energy increases
Explanation:
The average kinetic energy of the rice molecules increases as the pot is left on the cooking stove.
Heat is transferred to the pot by conduction from the heat source. The heat is then transferred to the rice in the cooking pot by convection.
- As the water in the pot heats up.
- The rice gains thermal energy.
- This causes the molecules of the rice particles to start vibrating.
- As the molecules vibrate about their fixed position, their thermal energy continues to increase.
- Therefore, the amount of heat absorbed by the rice increases with time and this actually cooks the food.
