Answer:
True
Explanation:
The volume of water displaced by an object completely submerged is its actual volume. It implies that in the container the object create a space of size for itself which is the volume of the object. This approach is used in calculating the density of many irregular solids from their measured masses.
The original results have not been replicated consistently and reliably.
<span>Answer: 100 ml
</span>
<span>Explanation:
1) Convert 1.38 g of Fe₂S₃ into number of moles, n
</span>i) Formula: n = mass in grass / molar mass
<span>
ii) molar mass of </span><span>Fe₂S₃ =2 x 55.8 g/mol + 3 x 32.1 g/mol = 207.9 g/mol
</span>
iii) n = 1.38 g / 207.9 g/mol = 0.00664 moles of <span>Fe₂S₃
</span>
<span>2) Use the percent yield to calculate the theoretical amount:
</span>
<span>65% = 0.65 = actual yield/ theoretical yield =>
</span>theoretical yield = actual yield / 0.65 = 0.00664 moles / 0.65 = 0.010 mol <span>Fe₂S₃</span><span>
3) Chemical equation:
</span>
<span> 3 Na₂S(aq) + 2 FeCl₃(aq) → Fe₂S₃(s) + 6 NaCl(aq)
4) Stoichiometrical mole ratios:
</span>
<span>3 mol Na₂S : 2 mol FeCl₃ : 1 mol Fe₂S₃ : 6 mol NaCl
5) Proportionality:
</span>2moles FeCl₃ / 1 mol Fe₂S₃ = x / 0.010 mol Fe₂S₃
<span>
=> x = 0.020 mol FeCl₃
6) convert 0.020 mol to volume
</span>
<span>i) Molarity formula: M = n / V
</span>
<span>ii) V = n / M = 0.020 mol / 0.2 M = 0.1 liter = 100 ml
</span>
Answer:
1. True
2. False
3. False
4. True
Explanation:
A lab is an abbreviation for laboratory and it can be defined as a building that is equipped with scientific equipments and apparatus, which are used for performing scientific experiments, manufacturing of chemicals and drugs, research, testing and analysis of hypothesis in order to establish a theory.
Generally, laboratory scientists, technicians, students and anyone going into a laboratory is prohibited from taking in edible items such as food and water.
Basically, all laboratories are required to place a visible warning sign around the lab prohibiting the bringing in and ingestion of food in any form.
1. True: Tobacco products of all kinds are prohibited in lab.
2. False: Beverages are allowed in lab as long as they are in containers with lids. It's completely prohibited from the lab so as to prevent food poisoning.
3. False: Chewing gum is okay in the lab as long as you don't blow bubbles.
4. True: Food items should not be brought into the lab.
