Which of the following is not evidence of a chemical change?

A. a change in color

B. the production of a gas

C. the formation of a precipitate

D. the separation of particles

How many grams of water can be produced when 11.7 moles of ethane (C2H6) react with excess oxygen gas? Unbalanced equation: C2H6 + O2 → CO2 + H2O

What is a Cilla? (In drawing)

I am a solid at room temperature, have 3 valence electrons and I make foil. What am I?

How do you think this food web would be affected if the plants were eliminated A. only the French I would survive B. birds and nematodes would thrive C. the food web would completely collapse D. the food web would produce more bacteria to compensate

A 6.00 % (m/v) NaCl solution contains 37.5 g of NaCl. What is the total volume (V) of the solution in milliliters?

What does the electron cloud model describe A. Rapidly moving neutrons B. Rapidly moving protons C. A standing wave of electron wavicles surrounding the nucleus D. Rapidly moving nucleus

35mL of acid with an unknown concentration is titrated to completion using 63mL of 3.0 MNaOH. What is the concentration of the acid?

What is the number of lone electron pairs on the central atom of a molecule having a linear molecular geometry, such as clf2-?

Look carefully at Kw expression. If the [H+] changed from [1 x 10-7] to [1 x 10-4], the [OH-] will: A. remain the same B. increase C. decrease

What on a bird, besides it's feet, is chemically similar to scales? A. beak B. feathers C. wings