The combining of hydrogen and oxygen gas into liquid water is an example of what kind of change?

phase

chemical

physical

Which of the following reactions is a synthesis reaction? A) Cl2 + 2NaBr ⟶ Br2 + 2NaCl B) 4H + O2 ⟶ 2H20 C) 2Na + 2H20 ⟶ 2NaOH + H2 D) C7H16 + 1102 ⟶ 7CO2 + 8H20

I don't unerstand what I'm supposed to do for these Heat = mass * c * temp change 175g 0.79J/gC 75 C Heat = mass * c * temp change 352g 1.65J/gC 25 C Heat = mass * c * temp change 268g 4.18J/gC 40 C Heat = mass * c * temp change 74g 0.

An atom of aluminum in the ground state and an atom of gallium in the ground state have the same (1) mass (2) electronegativity (3) total number of protons (4) total number of valence electrons

According to table f which substance is most soluble in water.

A sample of 1.000 g of a compound containing carbon and hydrogen reacts with oxygen at elevated temperature to yield 0.692g H2O and 3.381g CO2. a. Calculate the masses of C and H in the sample. b. Does the compound contain any other elements

Which of the following has the highest critical temperature? H2 N2 NH3 H2O

Are there any good tips for organic chemistry reactions?

Why is there such a vast climate difference in these two areas of the grand canyon the inner canyon and north rim?

If an objects volume decreases but the mass stays the same why

47 When the pH of an aqueous solution is changed from 1 to 2, the concentration of hydronium ions in the solution is (1) decreased by a factor of 2 (2) decreased by a factor of 10 (3) increased by a factor of 2 (4) increased by a factor or 10