Answer:
Explanation:
A chemical change, as the name suggests, must result from a change in the chemical makeup and new substances are produced. A very common example is metal rusting.
A physical change can be observed without a change in chemical composition. No new substances are produces. Ripping paper and an ice cube melting are physical changes.
A rubber band stretching is a physical change. No new substances are made and the chemical makeup remains the same.
Answer:
physical
Explanation:
this is a physical action to create a change. does not involve chemicals or elements
(B) fluorous acid
(C) perfluoric acid
(D) hydrofluoric acid
(E) hypofluorous acid
B. 267 to 322 km per hour.
C. 105 to 177 km per hour.
D. 178 to 266 km per hour.
Answer:
Explanation:
We must look up the standard reduction potentials for the half-reactions.
ℰ°
Cr₂O₇²⁻ + 14H⁺ + 6e⁻ ⇌ 2Cr³⁺ + 7H₂O 1.36
Cl₂ + 2e⁻ ⇌ 2Cl⁻ 1.35827
2IO₃⁻ + 12H⁺ + 10e⁻ ⇌ I₂ + 6H₂O 1.195
Fe³⁺ + e⁻ ⇌ Fe²⁺ 0.771
(a) Cr³⁺/Cl₂
We reverse the sign of ℰ° for the oxidation half-reaction. Then we add the two half-reactions and their ℰ° values.
ℰ°/V
2Cr³⁺ + 7H₂O ⇌ Cr₂O₇²⁻ + 14H⁺ + 6e⁻ -1.36
Cl₂ + 2e⁻ ⇌ 2Cl⁻ 1.358 27
2Cr³⁺ + 3Cl₂ + 7H₂O ⇌ Cr₂O₇²⁻ + 6Cl⁻ + 14H⁺ 0.00
(b) Fe²⁺/IO₃⁻
ℰ°/V
Fe²⁺ ⇌ Fe³⁺ + e⁻ -0.771
2IO₃⁻ + 12H⁺ + 10e⁻ ⇌ I₂ + 6H₂O 1.195
10Fe²⁺ + 2IO₃⁻ + 12H⁺ ⇌ 10Fe³⁺ + I₂ + 6H₂O 0.424
The ℰ° values for the cells are
Answer:
Answer:
\boxed{\text{(a) 0.00 V; (b) 0.424 V}}
Explanation:
We must look up the standard reduction potentials for the half-reactions.
ℰ°
Cr₂O₇²⁻ + 14H⁺ + 6e⁻ ⇌ 2Cr³⁺ + 7H₂O 1.36
Cl₂ + 2e⁻ ⇌ 2Cl⁻ 1.35827
2IO₃⁻ + 12H⁺ + 10e⁻ ⇌ I₂ + 6H₂O 1.195
Fe³⁺ + e⁻ ⇌ Fe²⁺ 0.771
(a) Cr³⁺/Cl₂
We reverse the sign of ℰ° for the oxidation half-reaction. Then we add the two half-reactions and their ℰ° values.
ℰ°/V
2Cr³⁺ + 7H₂O ⇌ Cr₂O₇²⁻ + 14H⁺ + 6e⁻ -1.36
Cl₂ + 2e⁻ ⇌ 2Cl⁻ 1.358 27
2Cr³⁺ + 3Cl₂ + 7H₂O ⇌ Cr₂O₇²⁻ + 6Cl⁻ + 14H⁺ 0.00
(b) Fe²⁺/IO₃⁻
ℰ°/V
Fe²⁺ ⇌ Fe³⁺ + e⁻ -0.771
2IO₃⁻ + 12H⁺ + 10e⁻ ⇌ I₂ + 6H₂O 1.195
10Fe²⁺ + 2IO₃⁻ + 12H⁺ ⇌ 10Fe³⁺ + I₂ + 6H₂O 0.424
The ℰ° values for the cells are \boxed{\textbf{(a) 0.00 V; (b) 0.424 V}}
Explanation:
its right trust
Answer:
80.0
Explanation:
edge 2020
Answer:2p→1s
Explanation:
Frequency is inversely proportional to wavelength. The higher the frequency, the shorter that wavelength. The smaller the frequency the longer the wavelength. The frequency of light associated with 2p→1s is less than the frequency of light associated with 3p→1s since the latter represents transition from a much higher energy level. It follows that the wavelength associated with the former will be longer since its frequency is lesser. This deduction follows from our argument about the inverse relationship between frequency and wavelength.
Answer:
0.09 M/s is the initial rate when concentration of reactant A is 0.900 M.
Explanation:
A → B
1) Initial concentration of A = [A] =0.300 M
Rate constant of the reaction , k = ?
Rate equation for the second order kinetic is given as:
2) Rate of the reaction when initial concentration of A was 0.900M be R'.
[A] = 0.900M