Answer:
-177.9 kJ.
Explanation:
Use Hess's law. Ca(s) + CO2(g) + 1/2O2(g) → CaCO3(s) ΔH = -812.8 kJ 2Ca(s) + O2(g) → 2CaO(s) ΔH = -1269.8 kJ We need to get rid of the Ca and O2 in the equations, so we need to change the equations so that they're on both sides so they "cancel" out, similar to a system of equations. I changed the second equation. Ca(s) + CO2(g) + 1/2O2(g) → CaCO3(s) ΔH = -812.8 kJ 2CaO(s) → 2Ca(s) + O2(g) ΔH = +1269.8 kJ The sign changes in the second equation above since the reaction changed direction. Next, we need to multiply the first equation by two in order to get the coefficients of the Ca and O2 to match those in the second equation. We also multiply the enthalpy of the first equation by 2. 2Ca(s) + 2CO2(g) + O2(g) → 2CaCO3(s) ΔH = -1625.6 kJ 2CaO(s) → 2Ca(s) + O2(g) ΔH = +1269.8 kJ Now we add the two equations. The O2 and 2Ca "cancel" since they're on opposite sides of the arrow. Think of it more mathematically. We add the two enthalpies and get 2CaO(s) + 2CO2(g) → 2CaCO3(s) and ΔH = -355.8 kJ. Finally divide by two to get the given equation: CaO(s) + CO2(g) → CaCO3(s) and ΔH = -177.9 kJ.
Calcium is stored in bones in the body
Option A
The price elasticity of demand measures buyers’ responsiveness to a change in the price of a good.
<u>Explanation:</u>
Price elasticity of demand holds the responsiveness of need subsequent a variation in a product's cost. In different terms, it’s a process to comprehend out the responsiveness of buyers to inconstancies in cost. Price elasticity estimates the responsiveness of the measure necessitated or outfitted of a good to a shift in its demand.
The price elasticity of demand is the rate fluctuation in the amount demanded of a good or assistance distributed by the percentage shift in the price. Considering the quantity demanded habitually declines with value, the price elasticity coefficient is essentially forever negative.
Answer:
The answer to your question is 150 ml
Explanation:
Data
Volume 1 = 25 ml
Concentration 1 = 0.6 M
Volume 2 = ?
Concentration 2 = 0.1 M
Formula
Volume 1 x Concentration 1 = Volume 2 x Concentration 2
Solve for Volume 2
Volume 2 = (Volume 1 x Concentration 1)/Concentration 2
Substitution
Volume 2 = (25 x 0.6) / 0.1
Simplification
Volume 2 = 15 / 0.1
Result
Volume 2 = 150 ml