Specific heat of cast iron is 0.46 kJ / kg K.
Energy change = 0.46 kJ / kg K * 3 kg * (120 - 30) K = 124.2 kJ
Answer:
The answer is 37amu
Explanation:
We are given:
Chlorine-35: atomic mass =35 amu and percent abundance =75.5% ≡ 0.755
Chlorine-37: atomic mass = x amu and percent abundance =24.5% ≡ 0.25
From table, relative atomic mass of Chlorine is 35.5
⇒(0.755 × 35) + (24.5 × x) = 35.5
26.402 + 24.5x = 35.5
∴ x = 9.075 ÷ 24.5 = 0.37 ≡ 37.
∴ mass of Chlorine 37 = 37amu
The molar ratio of Li to N2 in the equation 6Li + N2 —> 2Li3N is:
6 moles Li / 1 mole N2
This is because this equation is balanced, and therefore the mole ratios exist just as they do in the reactants of the equation (there are 6 parts Li per each part N2 in order to create the product; this also holds true for moles).
Hope this helps!
Answer:
S is the limiting reagent.
Explanation:
To find the limiting reactant we must first write the balanced chemical reaction. It must be correctly balanced so that we can find the proper mole ratios.
2 S (s) + 3 O2 (g) + 4 NaOH (aq) → 2 Na2SO4 (aq) + 2 H2O (l)
After this we will convert our measurements to moles. For mass we do this by dividing by the molar mass.
2g ÷ 32.06 = 0.06238mol S
3g ÷ 32.00 = 0.09375mol O₂
Now that we have the moles of each of the reactants, we can multiply them by their mole ratio with a reactant.
0.06238mol S × 2/2 = 0.06238mol H2O
0.09375mol O₂ × 2/3 = 0.06250mol H2O
S is our limiting reagent because it makes the smaller amount of moles.
