How many times more acidic is a solution with a pH of 2 than one with a pH of 4?

Use the kinetic energy equation to explain why speed has a greater impact on kinetic energy than mass.

Lerok [7]

Answer: Hopefully this helps! sorry if not. :))

Speed has a greater impact on mass because its increases in velocity have an exponentially greater impact on translational kinetic energy because kinetic energy is proportional to velocity squared. Doubling an object's mass would only double its kinetic energy, however doubling its momentum would quadruple its velocity.

3 0

2 years ago

Write the oxidation and reduction half reactions;

luda_lava [24]

Answer:

a)

$Fe^{2+}$ ⇒ $Fe^{3+}+e^-$

$Br_2+2e^-$ ⇒ $2Br^-$

b)

$Mg$ ⇒ $Mg^{2+}+2e^-$

$Cr^{3+}+e^-$ ⇒ $Cr^{3+}$

Explanation:

A)

Remember that positive number superscripts mean electrons lack and negative numbers mean electrons 'excess' (if we compare it with the neutral element). So, for the case of Fe2+ which is converted to Fe3+, we know that in Fe2+ there is a two electrons lack, while in Fe3+ there is a 3 electrons lack; it means that Fe2+ was converted to Fe3+ but releasing one electron:

$Fe^{2+}$ ⇒ $Fe^{3+}+e^-$

The same analysis is applied to Br2; Br2 is a molecule which is said to have a zero superscript because it is an apolar covalent bond; and it is converted to Br-, which, according to what I wrote above, means that there is a one electron excess. So, Br2 must have received an electron in order to change to Br-; but Br2 can't change to Br- as simple as that because Br2 is a molecule, not an atom; it is a molecule that has two Br atoms, so, Br2 must give two Br- ions as products, but receiving one electron for each one:

$Br_2+2e^-$ ⇒ $2Br^-$

b)

Applying the same, in Mg2+ there is a 2 electrons lack, and in Mg is not electron lack (its superscript is zero), so Mg must have released two electrons in order to change to Mg2+:

$Mg$ ⇒ $Mg^{2+}+2e^-$

Cr3+ has a 3 electrons lack, and Cr2+ a two electrons one, so, Cr3+ must receive an electron to convert to Cr2+:

$Cr^{3+}+e^-$ ⇒ $Cr^{3+}$

3 0

3 years ago

Read 2 more answers

Please, I need at least accurate answers for my Sound Knowledge Check for my Science class.

Alla [95]

Answer:

1.A

2.A

3.C