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3 years ago

What is a controlled variable ?

1 answer:

4 0

A control variable is the one element that is not changed throughout an experiment, because its unchanging state allows the relationship between the other variables being tested to be better understood.

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You do not know an object's velocity until you know its what?

luda_lava [24]

You do not know an object's velocity until you know its speed and direction

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4 years ago

2. What is frequency? Fre

Darina [25.2K]

Answer:

Frequency is the rate at which something occurs or is repeated over a particular period of time

Explanation:

The frequency is like wave patterns including sound, electromagnetic waves, electrical signals, or other waves, this expresses the number of cycles of the repetitive waveform per second.

4 0

3 years ago

Read 2 more answers

What some advantages of using concrete?

Anastaziya [24]

It changes with the temperature

5 0

3 years ago

The elementary gas-phase reaction2A → Bis carried out in a constant-volume batch reactor where 50% conversion is achieved in 1 h

Zina [86]

Answer:

$V=5000dm^3$

Explanation:

Hello,

In this case, for the STR reactor carrying out this chemical reaction, the material balance is:

$\frac{dC_A}{dt}=r_A\\\\\frac{dC_A}{dt}=-kC_A^2$

Thus, with the given information we compute the rate constant as follows:

$C_A_0 \frac{dX_A}{dt}=kC_A_0^2(1-X_A)^2\\\\\int\limits^{0.5}_0 {\frac{dX_A}{(1-X_A)^2} } \,=kC_A_0t\\\\\frac{0.5}{1-0.5}=k*0.2\frac{mol}{dm^3}*1h\\ \\k=\frac{1}{(0.2\frac{mol}{dm^3})*1h} \\\\k=5\frac{dm^3}{mol*h}$

Now, for the CSTR we have the following design equation in terms of conversion for finding the volume:

$V=\frac{F_A_0*X_A}{-r_A}\\\\V=\frac{F_A_0*X_A}{k*C_A_0^2(1-X_A)^2}$

Therefore, it turns out:

$V=\frac{500\frac{mol}{h} *0.5}{5\frac{dm^3}{mol*h} *(0.2\frac{mol}{dm^3} )^2(1-0.5)^2}\\\\V=5000dm^3$

Best regards.

7 0

3 years ago

How many grams of nitrogen in 7.3 x 10^24 molecules of NaNO3

dem82 [27]

Answer:

Explanation:

Convert molecules to moles:

1 mole of NaNO₃= 6.02 x 10^23 molecules of NaNO₃

7.3 x10^24/(6.02 x 10^23)=12mol NaNO₃

Find molar mass:

NaNO₃=1 mole of Na and 1mole of N and 3mole of O

Find grams:

14.01g x 12= 168.12 g of N

3 0

3 years ago