I fell D is the correct answer
Answer: C. Electrochemical cells involve oxidation-reduction reactions.
Explanation: Oxidation occurs at the anode, and reduction occurs at the cathode.
When burning sodium (Na) in oxygen (O2), you get sodium oxide (Na2O) and/or sodium peroxide (Na2O2). At high pressures, you can additionally get sodium superoxide (NaO2).
4 Na + O2 → 2 Na2O, and then partially 2 Na2O + O2 → 2 Na2O2.
Under normal conditions, approximately 20% of the mixture is Na2O2.
6 Na + 2 O2 → 2 Na2O + Na2O2
hope it helps
Answer:
Explanation:
250 cm^3 of 0.2 moldm-3 H2SO4 can be prepared from 150cm^3 of 1.0 moldm^-3 by dilution.
150cm^3 of the 1.0 moldm^-3 stock solution is measured out using a measuring cylinder and transferred into a 250 cm^3 standard volumetric flask and made up to mark. The resulting solution is now 250cm^3 of 0.2 moldm-3 H2SO4.
C. Speed is how fast, velocity has direction and acceleration is a change in velocity.
