The displacement function is given by : r = bt2i + ct3j meters
The velocity function is the derivative of the displacement:
v = r' = 2bti + 3ct2j meter / second
Now, for <span> the velocity vector make an angle of 45.0∘ with the x- and y-axes, the i and j components have to be equal:
</span>2bt = 3ct2 (Now solve for t)
2bt = t (3ct)
either t = zero (rejected)
or t = 2b / 3c seconds (accepted)
Answer:
U= 238g/mol
U2O5= 556g/mol
Explanation:
Since U= 238
O=16
U3O5= 2(238)+3(16)=556g/mol
Answer:
False
Explanation:
Boron is an exception to the octet rule because it possesses less than eight electrons. Boron has five electrons with three of them being valence electrons and therefore has an incomplete octet. It readily forms compounds in which it has six valence electrons, rather than the usual eight.
Hope that helps.
Answer:
Acid - dilute nitric acid
Metal oxide - zinc oxide, zinc hydroxide or zinc carbonate
Explanation:
Zinc Nitrate is produced by carrying out a reaction between the following metal oxides and acid
Acid - dilute nitric acid as concentrated nitric acid produces ammonium nitrate
Metal oxide - zinc oxide, zinc hydroxide or zinc carbonate
Hence the correct answer is
Acid - dilute nitric acid
Metal oxide - zinc oxide, zinc hydroxide or zinc carbonate
Answer:
412.1kJ
Explanation:
For the reaction , from the question -
4Fe (s) + 3O₂ (g) → 2Fe₂O₃ (s)
Δ Hrxn = Δ H°f (products) - Δ H°f (reactants)
In case the compound is in its standard state , enthalphy of formation is zero
Hence ,
for the above reaction ,
ΔHrxn =( 2 * Δ H° (Fe₂O₃ )) - [ ( 4 *Δ H° Fe ) + (3 * Δ H° O₂ )]
The value for Δ H°(Fe₂O₃ ) = - 824.2kJ/mol
Δ H° Fe = 0
Δ H° O₂ = 0
Putting in the above equation ,
ΔH rxn = ( 2 * Δ H° (Fe₂O₃ )) - 0
ΔHrxn = 2× - 824.2 kJ / mol = - 1648.4 kJ/mol
- 1648.4 kJ/mol , this much heat is released by the buring of 4 mol of Fe.
Hence ,
for 1 mol of Fe ,
- 1648.4 kJ/mol / 4 = 412.1kJ