Answer:
2.67 × 10⁻²
Explanation:
Equation for the reaction is expressed as:
CaCrO₄(s) ⇄ Ca₂⁺(aq) + CrO₂⁻⁴(aq)
Given that:
Kc=7.1×10⁻⁴
Kc= ![[Ca^{2+}][CrO^{2-}_4]](https://tex.z-dn.net/?f=%5BCa%5E%7B2%2B%7D%5D%5BCrO%5E%7B2-%7D_4%5D)
Kc= [x][x]
Kc= [x²]
7.1×10⁻⁴ = [x²]
x = 
x = 0.0267
x = 
The balanced equation for the reaction between Mg and O₂ is as follows
2Mg + O₂ --> 2MgO
stoichiometry between Mg and O₂ is 2:1
number of Mg reacted - 4.00 mol
if 2 mol of Mg reacts with 1 mol of O₂
then 4.00 mol of Mg requires - 1/2 x 4.00 = 2.00 mol of O₂
then the mass of O₂ required - 2.00 mol x 32.0 g/mol = 64.0 g
64.0 g of O₂ is required for the reaction
Answer:
See Explanation ( = same answer for earlier question)
Explanation:
The Arrhenius acid-base theory defines an acid as a compound which when added into water increases the hydronium ion (H₃O⁺) concentration and the base as a compound which when added into water increases the hydroxide (OH⁻) ion concentration. As such, an acid-base reaction is limited to proton transfer to only OH⁻ ions forming water. Such would imply that all acid-base reactions produce water only in addition to a salt. This is not always the case as conjugate base anions for many substances can receive proton transfer.
Example: The reaction HOAc + NaCN => HCN + OAc- will occur in aqueous media because the proton (H⁺) on acetic acid (HOAc) will transfer to the cyanate ion forming hydrocyanic acid (HCN). Such occurs because the CN⁻ ion is a stronger conjugate base than the acetate ion (OAc⁻) and forms the more stable weak acid. Such is the basis of the Bronsted-Lowry Acid-Base system and states that an acid (proton donor) will transfer its ionizable hydrogen to a conjugate base (proton acceptor) if the transfer forms a weaker acid.
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Answer:
half lives passed=5
given sample=90g
sample left=2.8125g
Explanation:
no. of half lives=total time/half life
no.=19days/3.8days
no.=5 days
after 5 half lives sample left=2.8125g
