Explanation:
sodium atom is neutral while sodium ion is a charged specie with a charge of +1
250 --> 125 --> 62.5 --> 31.25
each arrow equals one half life, so 3 half lives
14 days/ 3 half lives =
4.67 days = half life
The molarity of KOH is 0.1055 M
<u><em> calculation</em></u>
Step 1: write the equation for reaction between H₂C₂O₄.2H₂O and KOH
H₂C₂O₄.2H₂O + 2 KOH → K₂C₂O₄ +4 H₂O
step 2: find the moles of H₂C₂O₄.2H₂O
moles = mass÷ molar mass
from periodic table the molar mass H₂C₂O₄.2H₂O= (1 x2) +(12 x2) +(16 x4) + 2(18)=126 g/mol
= 0.2000 g ÷ 126 g/mol =0.00159 moles
step 3: use the mole ratio to calculate the moles of KOH
H₂C₂O₄.2H₂O : KOH is 1:2
therefore the moles of KOH =0.00159 x 2 = 0.00318 moles
step 4: find molarity of KOH
molarity = moles/volume in liters
volume in liters = 30.12/1000=0.03012 L
molarity is therefore = 0.00318/0.03012 =0.1055 M
Answer:
Explanation:
Polyatomic ions are ions (usually anions) that are made up of more than one atom. In order to determine the charge of anions, one can first identify the charge of the metal (which forms the cation) in a compound (which is usually easy to know) before predicting the charge of the anion. The charges are usually exchanged to form denominator of the other reacting atom/molecule, but if divisible, they are divided first before the exchange.
(a) The polyatomic ion in KNO₂ is NO₂ with the ionic equation below showing it's charge
KNO₂ ⇒ K⁺ + NO₂⁻
From the above, we can deduce that the charge of NO₂ is "1-"
(b) The polyatomic ion in CaSO₄ is SO₄ with the ionic equation below showing it's charge
CaSO₄ ⇒ Ca²⁺ + SO₄²⁻
The charge of SO₄ from the above equation is "2-"
(c) The polyatomic ion in Mg(NO₃)₂ is NO₃ with the ionic equation below showing it's charge
Mg(NO₃)₂ ⇒ Mg²⁺ + NO₃⁻
From the above equation, it can be deduced that the charge of NO₃ is "1-"
For the suger solution- it is cloudy
for the water- is clear