Answer:
A and F i think
Explanation:
Freezing point depression is a colligative property observed in solutions that results from the introduction of solute molecules to a solvent. The freezing points of solutions are all lower than that of the pure solvent and is directly proportional to the molality of the solute
These rocks were either roasted or exposed to severe weathering
The temperature change is 23 °C.
<em>q = mC</em>Δ<em>T</em>
Δ<em>T</em> = <em>q</em>/(<em>mC</em>)
<em>m</em> = 355 g
∴ Δ<em>T</em> = (34 000 J)/(355 g × 4.184 J·°C⁻¹g⁻¹) = 23 °C
<em>Note</em>: The answer can have only <em>two significant figures</em> because that is all you gave for the amount of heat absorbed.
Answer:
The correct answer is option E.
Explanation:
Mass of ferric oxide decomposed = 57.0 g
Moles of ferric oxide decomposed = 
According to reaction, 2 moles ferric oxide on combustion gives 824.2 kJ of heat.
Then heat given by on decomposition of 0.35625 mol of ferric oxide will be:
So, on decomposition of 57.0 grams of ferric oxide 147 kilo Joules of heat was released.
Answer: 6.1 g
Explanation:
between Mg and MgO theres a 1;1 MOLE RATIO
here's the balanced equation
2Mg + O2 ==> 2MgO
24g of magnesium is approximately 1 mole of magnesium so it produces 40 g of mgo which is also 1 mole of mgo thus 10/40 =0.25 moles of MgO so 0.25 moles of magnesium would be needed which is approximately 6.1 g
