Answer:
6. 7870 kg/m³ (3 s.f.)
7. 33.4 g (3 s.f.)
8. 12600 kg/m³ (3 s.f.)
Explanation:
6. The SI unit for density is kg/m³. Thus convert the mass to Kg and volume to m³ first.
1 kg= 1000g
1m³= 1 ×10⁶ cm³
Mass of iron bar
= 64.2g
= 64.2 ÷1000 kg
= 0.0642 kg
Volume of iron bar
= 8.16 cm³
= 8.16 ÷ 10⁶
Density of iron bar
= 7870 kg/m³ (3 s.f.)
7.
Mass
= 1.16 ×28.8
= 33.408 g
= 33.4 g (3 s.f.)
8. Volume of brick
= 12 cm³
Mass of brick
= 151 g
= 151 ÷ 1000 kg
= 0.151 kg
Density of brick
= mass ÷ volume
(3 s.f.)
The pillows because it is larger than paperback books, in this situation just think about which is larger, I pretty sure Andre is not going to hold the boxes in his hand.
hope I helped
The mass of 254 mL of water is 254 g. Since the density of water is 1g/mL, we can simply multiply the density 1g/mL by 254 mL of water and get 254 g as our answer. Since mL is in the numerator and denominator, mL cancels out and we are left with g only.
It has to be understood that 2 moles of oxygen are there in each mole of PbO2. Then it has to be calculated for 2 moles of oxygen.
Amount of oxygen = 2 * 5.43 moles
= 10.86 moles
Now it is also a fact that each mole of H2O contains 1 mole of oxygen. Then it can be easily concluded that 10.86 moles of water will be produced. I hope the procedure is clear enough for you to understand.
