Centimeters are units of length.
Answer:
Explanation:
We will need a balanced chemical equation with masses, moles, and molar masses.
1. Gather all the information in one place:
Mᵣ: 18.02
2Na + H₂O ⟶ 2NaOH + H₂
m/g: 72.0
2. Moles of H₂O
3. Moles of Na
The molar ratio is 2 mol Na/1 mol H₂O.
Answer:
The total amount of heat released is 68.7 kJ
Explanation:
Given that:
mass of water = 94.0 g
moles of water = 94 / 18.02 = 5.216
80⁰C ------> 0⁰C --------> -30⁰C
Q1 = m Cp dT
= 94 x 4.184 x (0 - 80)
= -31463.68 J
= -31.43 kJ
Q2 = 6.01 x 10^3 x 5.216
= - 31348.16 J
= -31.35 kJ
Q3 = - 94 x 2.09 x 30
= - 5893.8 J
= -5.894 kJ
Total heat = Q1 + Q2 + Q3 = -31.43 kJ + (-31.35 kJ ) + (-5.894 kJ
) = -68.7 kJ
Total heat released = -68.7 kJ
Note that the "negative sign" simply indicates heat released, therefore no need to put it in the answer.
<u>Given:</u>
Initial velocity (v1) = 0 m/s
Final velocity (v2) = 30 m/s
Acceleration (a) = 6.1 m/s2
<u>To determine:</u>
The time (t) taken to reach the final speed
<u>Explanation:</u>
Use the relation:
Acceleration (a) = [final velocity(v2) - initial velocity (v1)]/time (t)
t = (v2-v1)/a = 30-0/6.1 = 4.92 s
Ans: Time taken is around 4.9 s
