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.**

**Explanation:**

The lunar phase or Moon phase is the shape of the Moon's directly sunlit portion as viewed from Earth. The lunar phases gradually change over a synodic month as the Moon's orbital positions around Earth and Earth around the Sun shift.

**Answer:**

x = 0.45*28/3 = 4.2 g

**Explanation:**

showing work

N2 = 28 g/mole

3Mg + N2 → Mg3N2

3moles .. 28 g

0.45 moles .. x

x = 0.45*28/3 = 4.2 g (answer)

**Answer:**

**0.0253 M/s**

**Explanation:**

From the reaction

N₂ + 3H₂ → 2NH₃

The rate of reaction can be written as

Rate = - = - = +

From the above rate equation we can conclude that the rate of reaction of N₂ is equal to one third of the rate of reaction of H₂,

So,

Rate of reaction of molecular nitrogen =

Upon calculation, we get rate of reaction of molecular nitrogen = **0.0253 M/s**

**Answer:**

1. balance observation using "how much" = 5. quantitative instrument

2. graduated cylinder = 4. quantitaive instrument of volume

3. hypothesis proposed explanation= 7. qualitative descriptive observation

4. unit of volume= L

6. kg = primary unit of mass

**Explanation:**

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