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Combined and Co-ordinated Sciences (Chemistry)

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  • Why are these hydrangea flowers different colors?
    Each one is a pH indicator.
  • How can excessively acidic soil be dealt with?
    It can be neutralized with lime (calcium oxide, calcium hydroxide, calcium carbonate=limestone, or chalk).
  • Which gas fills bags of chips and snacks to make sure the food doesn't go rancid from exposure to oxygen?
    nitrogen
  • Why might someone swallow the insoluble magnesium hydroxide?
    It is an antacid.
  • What is KOH?
    caustic potash (potassium hydroxide)
  • Alkalis feel _____ to the skin (They convert the oils in your skin into _______).
    soapy/soap
  • Which letter is bases and which letter is alkalis?
    A is alkalis. B is bases.
  • What substance has the formula NH3?
    ammonia
  • Name one of the substances commonly referred to as "lime".
    calcium oxide, calcium hydroxide, calcium carbonate=limestone, or chalk
  • What do ALL metal oxides and hydroxides do?
    They all neutralize acids, whether soluble or not. They are bases.
  • What kind of reaction occurs when an acid is mixed with a base?
    a neutralization reaction
  • What is the formula for lye (caustic soda)?
    NaOH (used in making paper, soaps, and in cleaners)
  • What is NaOH?
    sodium hydroxide (lye)
  • Each plant grows best in certain pH soils. Which prefers more acidic soil, potatoes or onion?
    potatoes (prefer 4.5-6.0, whereas onions prefer 6.0-7.5)
  • The atmosphere is 78% nitrogen and 21% oxygen. Name the next three most common gases.
    argon (.9%) carbon dioxide (.04%) neon (.002%)...water vapor also OK (0%-3%)
  • Which gas is used in the Haber process to manufacture ammonia and fertilizers?
    nitrogen
  • What is the formula for limewater?
    CaOH (calcium hydroxide)
  • What is the formula for ammonia?
    NH3
  • Most bases are insoluble in water. Name a common alkali, a base that IS soluble.
    sodium hydroxide, potassium hydroxide, calcium hydroxide (limewater), ammonia (ammonium hydroxide)
  • What do you call a base that is soluble in water?
    an alkali
  • A flue-gas desulfurizer reduces emissions of what gas?
    sulfur dioxide
  • What do factories have to spray acidic waste with jets of slaked lime before the gases leave the chimneys?
    a flue-gas desulfurizer
  • How can excessively alkaline soil be handled?
    Add peat, compost or manure
  • How can we summarize a neutralization reaction?
    acid + base -> salt + water
  • What is the formula for caustic potash?
    KOH (used in making soap)