Answer:
5.15 moles
Explanation:
2zn + o2 = 2zno
5.15 2.57 5.15 moles
nzno=500/(16x2+65)= 5.15 moles
-> nzn = 5.15 x 2 ÷ 2 = 5.15 moles
Answer:
[HF]₀ = 0.125M
Explanation:
NaOH + HF => NaF + H₂O
Adding 20ml of 0.200M NaOH into 25ml of HF solution neutralizes 0.004 mole of HF leaving 0.004 mole NaF in 0.045L with 0.001M H⁺ at pH = 3. This is 0.089M NaF and 0.001M HF remaining.
=> 45ml of solution with pH = 3 and contains 0.089M NaF from titration becomes a common ion problem.
HF ⇄ H⁺ + F⁻
C(eq) [HF] 10⁻³M 0.089M (<= soln after adding 20ml 0.200M NaOH)
Ka = [H⁺][F⁻]/[HF]₀ => [HF]₀ = [H⁺][F⁻]/Ka
[HF]₀ = (0.001)(0.089)/(7.1 x 10⁻⁴) M = 0.125M
ANSWER: C) Law of Conservation of Mass
EXPLANATION: In the given cycle, it is seen that th sediments are layered and gets compressed into sedimentary rocks which eventually gets heated and compressed to form metamorphic rocks. But, the total amount of minerals present in the sediments remains the same throughout any stage of the cycle.
This proves the law of conservation of mass which states that mass can not be created nor be destroyed, it can only be transferred from one form to another. So, in this case, only phase transition occurred but the component which is mineral inside the sediments remains constant.
Therefore, the answer is law of conservation of mass.
12cm cubed.
Formula is length x width x height and in this case it would be 2x3x2 which equals 23
Answer: The density of lead will be 
Explanation:
Density is defined as the mass contained per unit volume.
Given : Mass of lead=
Volume of lead =
Putting in the values we get:
Thus density of lead will be
