Answer:
1. 3.70 g Na₂CO₃·10H₂O
2. 50.0 mL of the first solution
Explanation:
1. Prepare the solution
(a) Calculate the molar mass of Na₂CO₃·10H₂O
The molar mass of Na₂CO₃·10H₂O is 286.15 g/mol.
(b) Calculate the moles of Na₂CO₃·10H₂O
(c) Calculate the mass of Na₂CO₃·10H₂O
2. Dilute the solution
We can use the dilution formula to calculate the volume needed.
V₁c₁ = V₂c₂
Data:
V₁ = ?; c₁ = 0.0500 mol·L⁻¹
V₂ = 100 mL; c₂ = 0.0250 mol·L⁻¹
Calculation:
Answer:
Explanation:
Figure 6. An instant cold pack consists of a bag containing solid ammonium nitrate and a second bag of water. When the bag of water is broken, the pack becomes cold because the dissolution of ammonium nitrate is an endothermic process that removes thermal energy from the water.
Answer:
An atom that loses one or more valence electrons to become a positively charged ion is known as a cation, while an atom that gains electrons and becomes negatively charged is known as an anion.
Atomic number
atomic mass
group|family
periods
and element symbols
Answer:An oxygen atom usually has 8 protons, 8 neutrons, and 8 electrons. Looking at the periodic table, oxygen has atomic number 8 and atomic weight 15.999.
Explanation: