4,561.245 Joules
Q = Mass x Change in Temperature x Specific Heat
Q = 22.6 x 225 x .897
Taking into account the definition of density, the density of the sample is 0.5 
.
It is necessary yo know that density is defined as the property that matter, whether solid, liquid or gas, has to compress into a given space.
In other words, density allows you to measure the amount of mass in a certain volume of a substance.
Then, the expression for the calculation of density is the quotient between the mass of a body and the volume it occupies:
In this case, you know:
Then, replacing in the definition of density:
Solving:
<u><em>density= 0.5 </em></u><u><em /></u>
Finally, the density of the sample is 0.5 .
Learn more about density:
In chemistry, pH<span> is a numeric scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the concentration of hydronium ions. We calculate as follows:
pH = -log [H3O+]
pH = -log[</span><span>5.45 × 10–5 M]
pH = 4.3</span>
Answer:
Mass = 357.7 g
Explanation:
Given data:
Mass of Fe = 250 g
Mass of oxygen = 120 g
Mass of iron(III) oxide produced = ?
Solution:
Chemical equation:
4Fe + 3O₂ → 2Fe₂O₃
Number of moles of Fe:
Number of moles = mass/molar mass
Number of moles = 250 g/ 55.8 g/mol
Number of moles = 4.48 mol
Number of moles of O₂ :
Number of moles = mass/molar mass
Number of moles = 120 g/ 32 g/mol
Number of moles = 3.75 mol
Now we will compare the moles of reactants with product.
Fe : Fe₂O₃
4 : 2
4.48 : 2/4×4.48 = 2.24
O₂ : Fe₂O₃
3 : 2
3.75 : 2/3×3.75= 2.5
Less number of moles of Fe₂O₃ are produced by Fe thus it will act as limiting reactant.
Mass of Fe₂O₃:
Mass = number of moles × molar mass
Mass = 2.24 mol × 159.69 g/mol
Mass = 357.7 g
