At one minute, a persons's heart beats 72 times.
Therefore, in one hour or 60 minutes, a person's heart will beat (60×72) times, i.e., 4320 times
Answer is 4320 times
Answer:
3) NaCl.
Explanation:
<em>∵ ΔTf = iKf.m</em>
where, <em>i</em> is the van 't Hoff factor.
<em>Kf </em>is the molal depression freezing constant.
<em>m</em> is the molality of the solute.
<em>The van 't Hoff factor is the ratio between the actual concentration of particles produced when the substance is dissolved and the concentration of a substance as calculated from its mass. </em>
<em></em>
- For most non-electrolytes dissolved in water, the van 't Hoff factor is essentially 1.
<em>So, for sugar: i = 1.</em>
<em>∴ ΔTf for sugar = iKf.m = (1)(Kf)(2.0 m) = 2 Kf.</em>
<em></em>
- For most ionic compounds dissolved in water, the van 't Hoff factor is equal to the number of discrete ions in a formula unit of the substance.
For NaCl, it is electrolyte compound which dissociates to Na⁺ and Cl⁻.
<em>So, i for NaCl = 2.</em>
<em>∴ ΔTf for NaCl = iKf.m = (2)(Kf)(1.0 m) = 2 Kf.</em>
<em></em>
<em>So, the right choice is: 3) NaCl.</em>
<em></em>
KOH is a strong base, so [OH-] = 0.10 M = 1.0 x 10^-1 M
[H+][OH-] = Kw
Kw = 1.0 x 10^-14
[H+] = 1.0 x 10^-14 / 1.0 x 10^-1 = 1.0 x 10^-13 M
Particles in a:
gas are well separated with no regular arrangement.
liquid are close together with no regular arrangement.
solid are tightly packed, usually in a regular pattern.
Particles in a:
gas vibrate and move freely at high speeds.
liquid vibrate, move about, and slide past each other.
solid vibrate (jiggle) but generally do not move from place to place.
Liquids and solids are often referred to as condensed phases because the particles are very close together.
The following table summarizes properties of gases, liquids, and solids and identifies the microscopic behavior responsible for each property.
Answer:
Energy in foods is provided by macro-nutrients.
Explanation:
Nutrients are “environmental substances” used for growth, energy, and bodily functions of the organisms. Those nutrients that are required in larger amounts are called macro-nutrients.
There are 3 macro-nutrients needed by humans: lipids (fats), carbohydrates (sugar) and proteins. All these macro-nutrients gives energy in form of “calories”. For example:
- In carbohydrates, there are '4 calories' of energy per gram.
- In proteins, there are '4 calories' of energy per gram.
- And in lipids, there are '9 calories' of energy in one gram.
This means that if you look at a food label and it lists 10 grams of carbohydrates, 0 grams of protein, and 0 grams of fat, that food would contain 40 calories.
