Answer is: it takes 116,8 seconds to fall to one-sixteenth of its initial value
<span>
The half-life for the chemical reaction is 29,2 s and is
independent of initial concentration.
c</span>₀
- initial concentration the reactant.
c - concentration of the reactant remaining
at time.
t = 29,2 s.<span>
First calculate the rate constant k:
k = 0,693 ÷ t = 0,693 ÷ 29,2 s</span> = 0,0237 1/s.<span>
ln(c/c</span>₀) = -k·t₁.<span>
ln(1/16 </span>÷ 1) = -0,0237 1/s ·
t₁.
t₁ = 116,8 s.
Answer:
a) HNO3 -> H+ + NO3- disassociation of Nitric Acid; to yield a Nitrate ion and a Proton, H+, or as a Hydronium ion H3O+
b) H2S04 -> Disassociation of Sulfuric Acid; simple way- 2H+ + SO4- -
c) H2S hydrogen sulphide in water is an acid; thus H+ HS- disassociation.
d) NaOH -> dissociation of Na+ + OH-; this is complete; sodium hydroxide is deliquescent, meaning it will draw water - EVEN from the air! Strong Base
e) Na2CO3 -> 2Na+ CO3- - Ionization of sodium carbonate - a salt
f) Na2S04 -> 2Na+ + SO4 - - ionization of sodium sulphate - a salt
g) NaCl -> Na+ + Cl- ionization of the salt, Sodium Chloride
Explanation:
Salts ionize at different rates; acids or bases dissociate; these are mostly strong acids and NaOH, a strong base.
The given formula for heat, Q=mc(Tf-Ti), is the best way to solve such problems with changes in temperature. It can be said that m is the mass of the substance. C is the specific heat of the substance. The term (Tf-Ti) is the change in temperature.
Q = mc(Tf-Ti) = 480g(0.96 J/g-C)(234-22) = 97689.6 Joules of heat
The question is incomplete. The complete question is:
Calcium Carbide (CaC₂) is an unusual substance that contains a carbon anion (C₂²⁻). The reaction with water involves several steps that occur in rapid succession. CaC2 is a salt (notice that its name is similar to sodium chloride). When a salt dissolves in water, ions leave the crystal lattice and enter the aqueous (aq) solution. Write the relevant balanced chemical equation for the dissolution of CaC₂, in water.
Answer:
CaC₂(s) + 2H₂O(l) → Ca(OH)₂(aq) + C₂H₂(aq)
Explanation:
When a salt dissolves in water, it dissociates in its ions. In the Calcium Carbide, the cation is Ca⁺² and the anion is C₂²⁻, so the reaction is:
CaC₂(s) + 2H₂O(l) → Ca(OH)₂(aq) + C₂H₂(aq)
The base Ca(OH)₂ is soluble, so it will dissociate at Ca⁺ and OH⁻, but the C₂H₂ is stable and doesn't dissociate in the solution.
The answer is surface tension
