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.
Answer:
The mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
Explanation:
We are given that
Aqueous solution that contains 22.9% NaOH by mass means
22.9 g NaOH in 100 g solution.
Mass of NaOH(WB)=22.9 g
Mass of water =100-22.9=77.1
Na=23
O=16
H=1.01
Molar mass of NaOH(MB)=23+16+1.01=40.01
Number of moles =
Using the formula
Number of moles of NaOH
Molar mass of water=16+2(1.01)=18.02g
Number of moles of water
Now, mole fraction of NaOH
=
=0.882
Hence, the mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
Iron. Well actually steel, but iron is the closest.
By nonmetals, metals, and gases
Answer:
(1) 0.035 × 10²³
Explanation:
Step 1: Calculate the mass of Fe in 100 g of Haemoglobin
Haemoglobin contains 0.33% Fe, that is, there are 0.33 g of Fe per 100 grams of Haemoglobin.
100 g Hb × 0.33 g Fe/100 g Hb = 0.33 g Fe
Step 2: Convert 0.33 g of Fe to moles
We will use the molar mass of Fe (55.85 g/mol).
0.33 g × 1 mol/55.85 g = 5.9 × 10⁻³ mol
Step 3: Convert 5.9 × 10⁻³ moles of Fe to atoms
We will use Avogadro's number.
5.9 × 10⁻³ mol × 6.02 × 10²³ atoms/1 mol = 3.5 × 10²¹ atoms (= 0.035 × 10²³)