The Sun is currently a main sequence star and will remain so for another 4-5 billion years. It will then expand and cool to become a red giant, after which it will shrink and heat up again to become a white dwarf. The white dwarf star will run out of nuclear fuel and slowly cool down over many billions of years.
Answer: It's D
Explanation:
I just did this question and i picked C but it's actually D
5H2O2 + 2KMnO4<span>+ 3H2SO4 = 5O2 + 2MnSO4 + 8H2O + K2SO4
0,145 moles of KMnO4----------in--------1000ml
x moles of KMnO4---------------in------------46ml
x = 0,00667 moles of KMnO4
according to the reaction:
2 moles of KMnO4------------------5 moles of H2O2
0,00667 moles of KMnO4----------------x
x = 0,01668 moles of H2O2
0,01668 moles of H2O2---------in-----------50ml
x moles of H2O2--------------------in----------1000ml
<u>x = 0,334 mol/L H2O2</u></span>
<span>Avogadro's number
represents the number of units in one mole of any substance. This has the value
of 6.022 x 10^23 units / mole. This number can be used to convert the number of
atoms or molecules into number of moles. We do as follows:
4.50 mol Fe ( 6.022x10^23 atoms / 1 mol Fe ) = 2.71x10^24 atoms Fe present </span>
Answer:
The equilibrium position will shift towards the lefthand side.
Explanation:
[CoCl4] 2- (aq) + 6H2O (l) ⇌ [Co(H2O)6] 2+ (aq) + 4 Cl- (aq)
The equation written above in exothermic as written. That is, the forward reaction is exothermic. The equilibrium position is observable by monitoring the colour change of the solution. At the left hand side, the solution is blue but at the right hand side the solution is pink. Addition of heat (in a hot water bath) will shift the equilibrium towards the left hand side, that is formation of more [CoCl4] 2- making the solution to appear blue in colour.
