How much heat, in joules and in calories, must be added to a 75.0–g iron block with a specific heat of 0.449 j/g °c to increase its temperature from 25 °c to its melting temperature of 1535 °c?

Acompound has a molar mass of 92.02 grams/mole, and its percent composition is 30.4% nitrogen (n) and 69.6% oxygen (o). what is its molecular formula? a. n2o4 b. no2 c. n2o d. n4o2

What effect would average population growth have on land usage? a. urban use of land would rise to more than 30 percent of available land. b. industrial use of land would rise to more than 30 percent of available land. c. the percentage of available land used as cropland would stay the same. d. cropland would fall to about 10 percent of available land.

Balance the following reaction. as2s3 + 9o2 → 2as2o3 + so2