Answer:
The answer to your question is: 6.55 x 10 ²³ atoms of Br
Explanation:
CH2Br2 = 37.9 g
MW CH2Br2 = (12 x 1) + (2 x 1) + (80 x 2) = 174 g
174 g of CH2Br2 ------------------ 160 g of Br2
37.9 g of CH2Br2 --------------- x
x = 37.9 x 160/174 = 34.85 g of Br
1 mol of Br ----------------- 160 g Br2
x ---------------- 174 g Be2
x = 174 x 1 /160 = 1.088 mol of Br2
1 mol of Br ----------------- 6.023 x 10 ²³ atoms
1.088 mol of Br ------------- x
x = 1.088 x 6.023 x 10 ²³ / 1 = 6.55 x 10 ²³ atoms
Answer:
300.9mL
Explanation:
Given parameters:
V₁ = 280mL
T₁ = 22°C
T₂ = 44°C
Unknown:
V₂ = ?
Solution:
To solve this problem, we apply Charles's law;
it is mathematically expressed as;

We need to convert the temperature to kelvin;
T₁ = 22°C = 22 + 273 = 295K
T₂ = 44°C = 44 + 273 = 317K
Input the parameters and solve;
= 
V₂ x 295 = 280 x 317
V₂ = 300.9mL
Answer:
to show that atoms are conserved in chemical reactions
Explanation:
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>
Endocytosis
Process by which the cell surrounds and takes particles into the cell
Exocytosis
Secretion of material out of the plasma membrane