The heat that is needed to raise the temperature of 78.4 g of aluminium from 19.4 °c to 98.6°c is 5600.77 j
<u><em>calculation</em></u>
Heat(Q) = mass(M) x specific heat capacity (C) x change in temperature(ΔT)
where;
Q=?
M = 78. 4 g
C=0.902 j/g/c
ΔT=98.6°c -19.4°c =79.2°c
Q is therefore = 78.4 g x 0.902 j/g/c x 79.2°c =5600.77 j
Yes the answer is 1s22s22p63s23p64s23d5
Answer:
Synthesis - 4
reversible- 2
exchange- 1
decomposition-3
Explanation:
In synthesis reaction two or more components combines to form a single product. example 2H2+O2⇒2H2O
In reversible reaction two reactants combine to form two products . The products then reacts and forms back the reactants. example N2 +3H2 ⇒2NH3
In exchange reaction there is an alternation of ions of reactants to form new products. AB+CD ⇒AC + BD
In decomposition reaction, molecules of a compound break down by the action of heat or light or catalyst. example CaCO3 ⇒CaO +CO2
Answer:

Explanation:
When calculating an empirical formula from percentages, assume you have a 100g sample. This allows you to convert the percentages directly to grams, because X % of 100g is X grams.
So:
24.42 % = 24.42 g Ca, 17.07% = 17.07g N, 58.5% = 58.5g O
The next step is to divide each mass by their molar mass to convert your grams to moles.
24.42/40.08 = 0.6092 mol
17.07/14.01 = 1.218 mol
58.85/15.99 = 3.680 mol
Then you will divide all of your mol values by the SMALLEST number of moles. This gives you whole numbers that are the mole ratio (subcripts) of the empircal formula.
0.6092 mol/0.6092 mol = 1
1.218 mol/0.6092 mol = 2
3.680 mol/0.6092 mol = 6
So the empirical formula is 
The energy required to raise the temperature of 3 kg of iron from 20° C to 25°C is 6,750 J( Option B)
<u>Explanation:</u>
Given:
Specific Heat capacity of Iron= 0.450 J/ g °C
To Find:
Required Energy to raise the Temperature
Formula:
Amount of energy required is given by the formula,
Q = mC (ΔT)
Solution:
M = mass of the iron in g
So 3 kg = 3000 g
C = specific heat of iron = 0.450 J/ g °C [ from the given table]
ΔT = change in temperature = 25° C - 20°C = 5°C
Plugin the values, we will get,
Q = 3000 g × 0.450 J/ g °C × 5°C
= 6,750 J
So the energy required is 6,750 J.