Answer:
32.3%
Explanation:
Percent yield is defined as:
Actual yield (125.5g) / Theoretical Yield * 100
To find theoretical yield we have to find the moles of aluminium. As 2 moles of Al produce 2 moles of AlCl3, the moles of Al = Moles AlCl3.
With these moles we can find the mass assuming a 100% of yield (Theoretical Yield) as follows:
<em>Moles Al = Moles AlCl3 (Molar mass Al = 26.98g/mol)</em>
72g Al * (1mol / 26.98g) = 2.67 moles AlCl3
<em>Mass AlCl3 (Molar mass: 133.34g/mol)</em>
2.67 moles AlCl3 * (133.34g / mol) = 355.8g AlCl3
Percent Yield = 125.5g / 355.8g * 100 =
<h3>32.3% </h3>
The correct answer is A. Urban areas have higher temperatures.
Explanation
Urban Area is a term to refer to cities. Urban areas are characterized by having a developed infrastructure (wide roads, vehicular bridges, wide platforms, tall buildings, residential areas, industrial areas, among others).
Recent studies affirm that urban areas are warmer than surrounding areas; This phenomenon is because the materials with are built buildings, roads, houses, and others, concentrate the sun's rays, increasing the temperature of cities. In addition, the lack of trees deepens this phenomenon, because the trees contribute to cooling by physicochemical processes such as evapotranspiration.
According to the above, it is possible to affirm that urban areas are hotter than their surrounding area because they lack vegetation, and the materials with which it is built contribute to the increase in temperature.
On the other hand, urban areas are characterized by habitat fragmentation, more problems with soil erosion, and less rain infiltration into the soil.
Learn more in: brainly.com/question/23587978
Answer:
4.74 × 10³ mg
Explanation:
Given data
- Health risk limit for chloroform in groundwater: 60.0 g/L
- Volume of the sample of groundwater: 79.0 mL = 79.0 × 10⁻³ L
The maximum mass of chloroform that there could be in the sample of groundwater to meet the standards are:
79.0 × 10⁻³ L × 60.0 g/L = 4.74 g
1 gram is equal to 10³ milligrams. Then,
4.74 g × (10³ mg/1 g) = 4.74 × 10³ mg
