Chemistry, 07.06.2020 05:59 lovely90

1. When water boils, water vapor is produced and escapes into the air. What best describes this change? 2. When iron combines with oxygen in a moist environment, rust forms because of a
~ chemical reaction
~ change in temperature
~ physical change
3. Two clear liquids are poured together in a flask. They begin to smoke, change color and the flask begins to feel warm to the touch. What type of change occurred?
~chemical and endothermic
~chemical and exothermic
~physical and exothermic
4. Can a phase change (change of state) produce new compounds?
~No, because physical changes occur
~Yes, because atoms can bond together to form new substances
~No, because chemical changes occur
5. Which is true of any physical or chemical reaction?
~Mass decreases
~Mass increases
~Mass is conserved

Answers: 3

Show answers

Another question on Chemistry

Chemistry, 22.06.2019 05:50

Why doesn't heat added to water make the tempature rise above 100c

Answers: 2

Answer

Chemistry, 22.06.2019 22:40

Percent ionization for a weak acid (ha) is determined by the following formula: percent ionization=[ha] ionized[ha] initial×100%for strong acids, ionization is nearly complete (100%) at most concentrations. however, for weak acids, the percent ionization changes significantly with concentration. the more diluted the acid is, the greater percent ionization.a certain weak acid, ha, has a ka value of 9.4×10? 7.part acalculate the percent ionization of ha in a 0.10 m solution.part bcalculate the percent ionization of ha in a 0.010 m solution

Answers: 1

Answer

Chemistry, 23.06.2019 03:00

Air pressure is measured in pascals. for a professional american football game, the ball should be inflated to about 90,000 pascals. scientists studied the effects of air temperature on the pressure inside american footballs by taking these steps: 1. prepare 100 footballs. 2. measure each football's air pressure. 3. divide footballs into 10 groups. 4. place the groups in different lockers cooled to different air temperatures. 5. after 12 hours, remove the footballs from lockers. 6. measure each football's pressure again. 7. compare the new pressures to the starting pressures. what two terms best describe the variable "air pressure inside the football" in this experiment? independent, qualitative independent, quantitative dependent, qualitative dependent, quantitative

Answers: 3

Answer

Chemistry, 23.06.2019 04:00

What changes occur in the reaction indicated by the equation? check all that apply. the hydrogen nucleus loses protons. the oxygen nucleus gains protons. the bond in h2 is broken, and new bonds are formed between hydrogen and oxygen atoms. each electron associated with a hydrogen atom is shared with an oxygen atom.

Answers: 3

Answer

You know the right answer?

1. When water boils, water vapor is produced and escapes into the air. What best describes this chan...

Questions