Answer is: <span>the pH value(level) is the independent variable.</span><span>
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Missing question: <span>We conducted an experiment where we added 0.5 g of lactose to 5 different test tubes all containing 5 different pH levels. What is the independent variable?
In this experiment pH level changes, so results depend on different pH values.
Mass of lactose is same during experiment,so t</span>he number of molecules of product formed per minute is the <span>dependent variable.</span>
Answer:
Velocity is vector quantity. So it needs <em>direction</em> in addoition to <em>speed</em>.
The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time. Velocity is equivalent to a specification of its speed and direction of motion.
Answer:
f = 33.34 Hz
Explanation:
A wave has a period of 0.03 seconds. It is required to find the frequency of a wave. The relation between time period and frequency is inverse. The time period of a wave is given by :
T = 1/f, f = frequency of wave

So, the frequency of the wave is 33.34 Hz.
From the given pH, we calculate the concentration of H+:
[H+] = 10^-pH = 10^-5.5
We then use the volume to solve for the number of moles of H+:
moles H+ = 10^-5.5M * 4.3x10^9 L = 13598 moles
From the balanced equation of the neutralization of hydrogen ion by limestone written as
CaCO3(s) + 2H+(aq) → Ca2+(aq) + H2CO3(aq)
we use the mole ratio of limestone CaCO3 and H+ from their coefficients, which is 1 mole of CaCO3 is to react with 2 moles of H+, to compute for the mass of the limestone:
mass CaCO3 = 13598mol H+(1mol CaCO3/2mol H+)
(100.0869g CaCO3/1mol CaCO3)(1kg/1000g)
= 680 kg
If the question includes x only than it’s value would be 1