Some physical evidence was obtained from a crime scene. For which of these pieces of evidence will forensic scientists conduct an identification test?

A.

a hair strand

B.

a black powder

C.

a glove

D.

bloodstains

A diatomic molecule (0.500 m) dissociates in a first order reaction with a rate constant, k, of 0.0775 sâ1. what is the half-life of this reaction? hints

What influences attraction for electrons?

Find the oxidizing agent and the reducing agent. 2Na (aq) + 2H2O (l) →2NaOH (aq) + H2 (g) C (s) + O2 (g) →CO2 (g) 2MnO-4 (aq) + 5SO2 (g) + 2H2O (l) →2Mn2 + (aq) + 5SO2-4 (aq) + 4H + (aq)

determine the empirical formula for a compound that has the following analysis: a 13.07 g sample of an unknown substance is composed of 9.48 g of barium, 1.66 g of carbon, and 1.93 g of nitrogen

How many moles of N are in 0.201 g of N 2 O?

Calculate the mass of 1.25 moles of Al2 (SO4) 3

which of Nature's erosions message do you think wears down a mountain or part 2 faster when water or ice why

We dissolve 5.00 grams of sugar, C12H22O11, in water to make 1.000 L of solution. What is the concentration of this solution expressed as a molarity?

What mass of carbon monoxide must be burned to produce 175 kj of heat under standard state conditions?

The Wittig reaction involves coupling between a phosphonium ylide and a carbonyl-containing molecule. If a chemist wants to use the Wittig reaction to synthesize 3-methyl-3-hexene, which reactants should be used?