Answer:D
Explanation:
Jus did this question & got it right
1. Na3PO4+Mg(NO3)2= NaNO3 + MgPO4
So this is not the answer.
2. Al+CuCl2= AlCl3+ Cu
So this is the answer.
3. Mg+O2= MgO2
So this is not an answer
4. Cl2+KI= KCl+I2
So this is also an answer
Hence B and C are answers
Answer:
The correct answer is - may not be typical, and participant burden.
Explanation:
The 24-hour recall is nothing but a retrospective method of diet assessment. In this method, an individual is interviewed about his or her diet consumption during the last 24 hours.
The disadvantages or limitations of this method include the inability of a single day's intake to describe the typical diet, multiple recalls to intake, cost and administration time; participant burden, have to recall to reliably estimate usual intake.
Answer:
25 mL
Explanation:
Step 1: Given data
- Concentration of the concentrated solution (C₁): 2 M
- Volume of the concentrated solution (V₁): ?
- Concentration of the diluted solution (C₂): 0.1 M
- Volume of the diluted solution (V₂): 0.500 L
Step 2: Calculate the volume of the concentrated NaCl solution
We will use the dilution rule.
C₁ × V₁ = C₂ × V₂
V₁ = C₂ × V₂ / C₁
V₁ = 0.1 M × 0.500 L / 2 M
V₁ = 0.025 L = 25 mL
The expected speed is v = 85.5 km/h
v = 85.5 km/h = (85.5 km/h)*(0.2778 (m/s)/(km/h)) = 23.75 m/s
If there is an uncertainty of 2 meters in measuring the position, then within a 1-second time interval:
The lower measurement for the speed is v₁ = 21.75 m/s,
The upper measurement for the speed is v₂ = 25.75 m/s.
The range of variation is
Δv = v₂ - v₁ = 4 m/s
The uncertainty in measuring the speed is
Δv/v = 4/23.75 = 0.1684 = 16.84%
Answer: 16.8%
