TLS Online TPP Program

#Question id: 4943


In what way were conditions on the early Earth of more than 3 billion years ago different from those on todayʹs Earth?

#11. Evolution and Behavior
  1. only early Earth had water vapor in its atmosphere.

  2. Only early Earth was intensely bombarded by large space debris.

  3. Only early Earth had an oxidizing atmosphere.

  4. Less ultraviolet radiation penetrated Earthʹs early atmosphere.

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TLS Online TPP Program

#Question id: 389

#1. Molecules and their Interaction Relevant to Biology

A weak acid HA has a pKa of 5.0.  If 1.0 mol of this acid and 0.1 mol of NaOH were dissolved in one liter of water, what would the final pH be?

TLS Online TPP Program

#Question id: 390

#1. Molecules and their Interaction Relevant to Biology

What are the properties arising due to varying concentrations of solute in a given solvent, irrespective of the nature of solute with respect to the solvent?

TLS Online TPP Program

#Question id: 391

#1. Molecules and their Interaction Relevant to Biology

In a hospital laboratory, a 10.0 mL sample of gastric juice, obtained several hours after a meal, was titrated with 0.1 M NaOH to neutrality; 7.2 mL of NaOH was required. The patient’s stomach contained no ingested food or drink, thus assume that no buffers were present. What was the pH of the gastric juice?

TLS Online TPP Program

#Question id: 393

#1. Molecules and their Interaction Relevant to Biology

Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O ↔ H2CO3. Carbonic acid (H2CO3) is a weak acid. If CO2 is bubbled into a beaker containing pure, freshly distilled water, which of the following graphs correctly describes the results?

TLS Online TPP Program

#Question id: 400

#1. Molecules and their Interaction Relevant to Biology

Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that ________.

TLS Online TPP Program

#Question id: 401

#1. Molecules and their Interaction Relevant to Biology

.Which of the following graphs describes the relationship between [H3O+] and pH?