Answer:
2 Cr(s) + 3 Fe(NO3)2(aq) = 3 Fe(s) + 2 Cr(NO3)3(aq)
Explanation:
I balanced this chemical equation so that both sides are equal, meaning that the mass of reactants is equal to mass of products.
C. Cello playing music at a concert
Answer:
1. 0.178 moles ; 2. 8x10²³ atoms ; 3. 7.22x10²³ molecules ; 4. 89.6 g ; 5. 1.34x10²² atoms ; 6. 1.67x10²⁵ molecules
Explanation:
1. Mass / Molar mass = Mol
5g / 28 g/m = 0.178 moles
2. 1 molecule of N₂ has 2 atoms, it is a dyatomic molecule.
4x10²³ x2 = 8x10²³ atoms
3. 1 mol of anything, has 6.02x10²³ particles
6.02x10²³ molecules . 1.2 mol = 7.22x10²³
4. 1 atom of C weighs 12 amu.
4.5x10²⁴ weigh ( 4.5x10²⁴ . 12) = 5.24x10²⁵ amu
1 amu = 1.66054x10⁻²⁴g
5.24x10²⁵ amu = (5.24x10²⁵ . 1.66054x10⁻²⁴) = 89.6 g
5. Molar mass NaCl = 58.45 g/m
1.3 g / 58.45 g/m = 0.0222 moles
1 mol has 6.02x10²³ atoms
0.0222 moles → ( 0.0222 . 6.02x10²³) = 1.34x10²²
6. Density of water is 1 g/mL, so 500 mL are contained in 500 g of water
Molar mass H₂O = 18 g/m
500 g / 18 g/m = 27.8 moles
6.02x10²³ molecules . 27.8 moles = 1.67x10²⁵
Answer:
–2.23 L
Explanation:
We'll begin by calculating the final volume. This can be obtained as follow:
Initial pressure (P₁) = 1.03 atm
Initial volume (V₁) = 3.62 L
Final pressure (P₂) = 2.68 atm
Final volume (V₂) =?
P₁V₁ = P₂V₂
1.03 × 3.62 = 2.68 × V₂
3.7286 = 2.68 × V₂
Divide both side by 2.68
V₂ = 3.7286 / 2.68
V₂ = 1.39 L
Finally, we shall determine the change in volume. This can be obtained as follow:
Initial volume (V₁) = 3.62 L
Final volume (V₂) = 1.39 L
Change in volume (ΔV) =?
ΔV = V₂ – V₁
ΔV = 1.39 – 3.62
ΔV = –2.23 L
Thus, the change in the volume of her lung is –2.23 L.
NOTE: The negative sign indicate that the volume of her lung reduced as she goes below the surface!
B. false is the answer of this question
