1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
astra-53 [7]
3 years ago
7

In an experiment, onion plants of different ages were exposed to various amounts of caffeine to determine the effect of caffeine

on cell growth. Temperature, amount of water, and light were kept constant. Which of these statements about the experiment is definitely true?
a. The results may not be valid because there were two variables.
b. The amount of caffeine used was a control.
c. Temperature, water, and light were the only variables.
d. Onion plants can be used to model the effects of caffeine on living things.
Chemistry
1 answer:
VladimirAG [237]3 years ago
5 0
A. is definitely true. The age of the plants and the amount of caffeine are two variables. The experimenter should have used only plants of the same age in order to determine the effect of caffeine.
b. is wrong. The amount of caffeine used was a variable.
c. is wrong. Temperature, water, and light were constants.
d. is wrong. The statement is a hypothesis that the experiment is trying to prove
You might be interested in
A buffer solution is made up of acetic acid (CH3COOH) and sodium acetate (NaCH3COO). The major equilibria in the buffer system a
katrin [286]

The equilibria showing how the acetate buffer adjusts to addition of a small amount of NaOH is:

  • CH3COOH(aq) + H2O(1) → H30+ (aq) + CH3COO (aq)

<h3>What is a buffer?</h3>

A buffer is a solution which resists changes to its pH when small amounts of strong base or acid is added to it.

Buffers are made from solutions of weak acids and their salts or weak bases and their salts.

The equilibria showing how a buffer made from acetic acid and sodium acetate (NaCH3COO) adjusts to addition of a small amount of NaOH is as follows:

  • CH3COOH(aq) + H2O(1) → H30+ (aq) + CH3COO (aq)

Addition of NaOH, a strong base will neutralize the hydronium ion, causing the acetic acid ionization equilibrium to shift to the right to produce more of the acetate ion, the conjugate base.

Learn more about acetate buffer at: brainly.com/question/17490438

3 0
2 years ago
Which is a property of a mineral<br><br> A. Size<br> B. Density <br> C. Odor<br> D. Age
ollegr [7]

B. density is the right answer

3 0
3 years ago
What type of bond does sodium and bromine form?
vitfil [10]
Sodium is a metal and bromine is a nonmetal so they form an ionic compound
nonmetals and nonmetals form covalent compounds
7 0
3 years ago
What are some chemical changes that occur at school at home and in nature
Travka [436]

Chemical changes are irreversible.

A chemical change that could happen at school would be when you have a chemistry experiment and you mix an acid and a base such as mixing hydrochloric acid with sodium hydroxide.

A chemical change that could happen at home would be baking a cake. You can't take the ingredients used in baking a cake back apart because they have changed their chemical composition.

A chemical change that happens in nature could be a forest fire. The burning of wood would be the chemical change in this case.

6 0
4 years ago
Calcium hydroxide sulphric acid =
koban [17]
Ca(OH)₂ + H₂SO₄ ⇒ CaSO₄↓ + 2H₂O
4 0
3 years ago
Other questions:
  • Which of these molecules has the same number of shared electron pairs as unshared electron pairs? (a) hcl, (b) h2s, (c) pf3, (d)
    14·2 answers
  • What element is in the lathanide family?
    6·2 answers
  • Which would aid a student in preparedness for a lab
    11·2 answers
  • Methods: Part A: Preparation of Buffers Make two buffers starting with solid material, which is the most common way to make buff
    8·1 answer
  • How many atoms are present in 4.0 Mol of sodium
    10·1 answer
  • Put the elements in order from lowest (1) to highest (6) electronegativity.
    14·1 answer
  • What is NOT a sign of chemical change?
    8·1 answer
  • Can u pls help me with this question ​
    13·1 answer
  • Can any person help me for this problem? Anyone's welcome
    6·1 answer
  • Calculate the amount of heat needed to convert 190.0 g of ice at -15 °C to water at 35 °C. Cp of ice=2.09J/g*c
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!