Calculate the change in energy requiredto convert 250. g of substance X from a gas at 121°C to a solid at - 49.0°C. Assume X has molar mass = 75.0 g/mol. Also, substance X has the following properties:

How many molecules are there in 65 g of silver nitrate (AgNO3) ? A. 3.82 * 1023 B. 2.3046 * 1023 C. 2.3046 * 1024 D. 3.82 * 1024 E. 2.3046 * 1012

When the fluid cools, the kinetic energy of the inolecules decreases. This causes the molecules to slow down and move closer together. Sines the molecules are closer together, the density of the fluid increases and the fluid sinks.

Whatlis the maximum number of electrons the n = 4 shell can contain

When na and s undergo a combination reaction, what is the chemical formula of the product?

Which of the following is notan example of matter? A) smoke B) heat C) water vapor D) air

What enables Dna to have so many variations with only 4 chemicals?

A chemist obtains 500.0 mL of a solution containing an unknown concentration of calcium iodide, CaI2. He pipets 15 mL of this solution into a 100 mL volumetric flask and dilutes to the mark.

Enthalpy changes that are difficult to measure directly can often be determined using Hess' Law to construct an enthalpy cycle.

Student follow up The ionic equation for the reaction between zinc and sulfuric acid is. Zn (s) + 2H (aq) - - Zn" (aq) + H2 (g) a State what has been oxidised in this reaction. Explain your answer in terms of electrons.

Consider the balanced chemical reaction below. When the reaction was carried out, the calculated theoretical yield for water was 176 grams, but the measured yield was 148 grams. What is the percent yield?