List 4 signs that show evidence of a chemical reaction

Based on the tiles shown, how many moles of oxygen gas (o2) are needed to produce 36.04 grams of water (h2o) when reacting with excess ethane in the equation 2c2h6 7o2 → 5co2 6h2o?

What type of bond does sodium and bromine form?

Write the formula equation for the following reaction. Ammonia reacts with hydrogen chloride to form ammonium chloride.

In the first recrystallization, after the solid has been dissolved in warm acetone, the solution is allowed to cool slowly to room temperature. In an older procedure the warm solution was placed directly into an ice bath.

The following equation shows the equilibrium in an aqueous solution of ammonia:NH3 (aq) + H2O (l) ⇌NH4 + (aq) + OH - (aq) Which of the following represents a conjugate acid-base pair? NH3 and H2ONH4 + and OH-H2O and OH-NH3 and

Which of the following statements is true about both nuclear fusion and nuclear fission? They occur in the sun. Heavy atoms are split. Two light nuclei combine. Some mass changes into energy.

What does the name iron (II) in a compound indicate about the cation? A an 11 + charge B a 2 - charge C a 2 + charge

Examples of balanced decomposition reactions

A birthday balloon had a volume of 14.1 L when the gas inside was at a temperature of 13.9 °C. Assuming no gas escapes, what is its volume when the balloon warms up to 22.0 °C?

Which of the following is not an indication of a chemical change?