Answer:
Barometric pressure is 942.3 cm of column of water.
Explanation:
We can measure barometric pressure by measuring the height h of a column of fluid (this column of fluid exerts the same pressure as the column of air of which we are measuring pressure) using the following formula:

Where ρ is the density of the fluid used and g the acceleration of gravity.
Knowing that both the column of mercury (to match units, we know that 698 mmHg are the same as 69.8 cmHg) and the column of water are representing the same pressure, we can match expressions and find h for the column of water:

Explanation:
Wind turbines generate electricity by following simple principle. Moving wind transfers energy to the to the blades of the wind mill which results in spinning of the blades. These blades are connected to internal shaft which also starts spinning. This spinning of shaft generates electricity which is further distributed to electrical substations to provide electricity to homes and businesses.
Step 1: Wind moves the blades of the turbine.
Step 2: Internal shaft spins
Step 3: Generator produces electricity
Step 4: Distribution lines carry electricity to substation
Answer:
D) SrCO3(s) + 2 HNO2(aq) → Sr(NO2)2 + H2O + CO2(g)
Explanation:
When an acid react with carbonate, it produces nitrate, carbon-dioxide gas and water molecule. When nitrous acid react with Strontium carbonate, three products are formed i. e. Strontium nitrate, carbon-dioxide gas and water. In the reaction, both nitrous acid and Strontium carbonate exchange their partners with each other and forming a different products.
The reaction between N₂ and F₂ gives Nitrogen trifluoride as the product. The balanced equation is;
N₂ + 3F₂ → 2NF₃
The stoichiometric ratio between N₂ and NF₃ is 1 : 2
Hence,
moles of N₂ / moles of F₂ = 1 / 2
moles of N₂ / 25 mol = 0.5
moles of N₂ = 0.5 x 25 mol = 12.5 mol
Hence N₂ moles needed = 12.5 mol
At STP (273 K and 1 atm) 1 mol of gas = 22.4 L
Hence needed N₂ volume = 22.4 L mol⁻¹ x 12.5 mol
= 280 L