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.)
PV = nRT
R = 0.0821 L * atm / mol * K
(ideal gas constant)
First, convert 735 torr to atm. Divide by 760.
(1 atm = 760 torr)
735 torr * 1 atm / 760 torr = 0.967 atm
Then, convert 37 C to Kelvin. Just add 273.
37 C = 310K
n = PV / RT
= (0.967)(2.07) / (0.0821)(310)
= 0.0786 mol
<span>0.0786 mol * 6.02 * 10^23 molecules / 1 mol = 4.73 * 10^22 molecules </span>
No of mole = reacting mass/ molar mass
No of mole = 0.06/56
No of mole = 0.00107mol....
Or...
1mole of iron contain 56gmol¯¹
:-x mole is contained in 0.06g
Porata
And you'll have..
x = 0.06/56
x = 0.00107mol.....
Some of the reactants or the products are in the gaseous phase.
The answer to this question is A
