Response:
4.5 m³
Resolution:
The statement indicates the presence of two blocks on a lid of a container with a volume of 9 m³. The lid's weight is equal to that of the two blocks. Thus, there were initially four blocks (or 4 atm pressure) acting on a volume of 9 m³.
After adding four additional blocks on the lid, the pressure rises from 4 atm to 8 atm (2 atm from the lid, 2 atm from the original blocks, and 4 atm from the new blocks).
Hence, The data established is,
P₁ = 4 atm
V₁ = 9 m³
P₂ = 8 atm
V₂ =?
Using Boyle's Law,
P₁ V₁ = P₂ V₂
Resolving for V₂,
V₂ = P₁ V₁ / P₂
Substituting values yields:
V₂ = (4 atm × 9 m³) ÷ 8 atm
V₂ = 4.5 m³
145 hours.
Explanation: Riding a bicycle for one hour expends 505 kcal of energy. Given that one gram of body fat equals 7.70 kcal, and 1 pound of body fat is equivalent to 454 grams:
1 lb = 454 g; thus, 21 lb = 21 × 454/1 = 9534 g. Moreover, converting 9534 g of body fat gives us 9534 × 7.70 kcal/1 = 73411.8 kcal. If riding for one hour burns 505 kcal, then to lose 73411.8 kcal, it would require 73411.8 kcal x 1 hour/505 kcal = 145 hours.
Answer:
evaporated
Explanation:
Once the solution evaporates, only salt will remain, as the sole other component in the solution is water.
Answer:
The correct options include choice 2, 3, and 6.
Explanation:
Density is identified as the mass of a substance per unit volume occupied by that substance.

The density remains constant for a given substance, regardless of variations in mass and volume hence it is considered an intensive property.
2. 20.2 g of silver in 21.6 mL of water and 12.0 g of silver also in 21.6 mL of water.
3. 15.2 g of copper in 21.6 mL of water and 50.0 g of copper in 23.4 mL of water.
6. 11.2 g of gold in 21.6 mL of water and 14.9 g of gold in 23.4 mL of water.
The same metals in both instances will yield consistent densities due to the fixed density of the metal.
Response:
The specific heat of the alloy 
Clarification:
Weight of the alloy
= 25 gm
Initial temperature
= 100°c = 373 K
Weight of the water
= 90 gm
Initial temperature of water
= 25.32 °c = 298.32 K
Final temperature
= 27.18 °c = 300.18 K
Using the energy balance equation,
Heat released by the alloy = Heat absorbed by the water
[[
-
] =
(
-
)
25 ×
× ( 373 - 300.18 ) = 90 × 4.2 (300.18 - 298.32)

This gives us the specific heat of the alloy.