All categories

3 years ago

What does it mean to control variables in an experiment

Chemistry

1 answer:

devlian [24]3 years ago

6 0

Answer:

Essentially, a control variable is what is kept the same throughout the experiment, and it is not of primary concern in the experimental outcome. Any change in a control variable in an experiment would invalidate the correlation of dependent variables (DV) to the independent variable (IV), thus skewing the results.

You might be interested in

Which has a higher percentage of the diequatorial-substituted conformer compared with the diaxialsubstituted conformer: trans-1,

kherson [118]

Answer:

cis-1-tert-butyl-3-methylcyclohexane will have a higher percentage of the diequatorial-substituted conformer when compared with the diaxialsubstituted conformer.

Explanation:

The two compound contain or have high stability with the substituent group is at equatorial position but the tert-betyl group in cis-1-tert-butyl-3-methylcyclohexane is larger than the methyl group in trans-1,4-dimethylcyclohexane.

Thus, the equatorial position will be more favorable for the substituent group in the cis-1-tert-butyl-3-methylcyclohexane, therefore having higher percentage of the diequatorial substituted conformer compared with that of diaxial-substituted conformer.

3 0

3 years ago

Give the name of one or more polysaccharides that matches each of the following descriptions:

adell [148]

Answer:

A Cellulose not digested by humans.

b. the storage form of carbohydrates in plants is starch

C amylose contains 1-4 glycosidic bond

D Glycogen and starch are highly branched polysaccharides.

Explanation:

8 0

2 years ago

The elemental analysis of an organic solid extracted from gum arabic (a gummy substance used in adhesives, inks, and pharmaceuti

Evgesh-ka [11]

Answer:

The molar mass of the organic solid is 120.16 g/mol.

The molecular formula of an organic solid is $C_4H_8O_4$

Explanation:

Let the molecular mass of an organic solid be $C_xH_yO_z$

$\Delta T_b=K_b\times m$

$Delta T_b=K_b\times \frac{\text{Mass of solid}}{\text{Molar mass of solid}\times \text{Mass of diphenyl in Kg}}$

where,

$\Delta T_f$ =Elevation in boiling point = $=1.5^oC$

Mass of organic solid= 0.561 g

Mass of diphenyl = 24.9 g = 0.0249 kg (1 kg = 1000 g)

$K_b$ = boiling point constant = 8.00 °C/m

m = molality

Now put all the given values in this formula, we get

$1.5^oC=8.00 ^oC/m\times \frac{0.561 g}{\text{Molar mass of solid}\times 0.0249 kg}$

${\text{Molar mass of solid}}=120.16 g/mol$

$\%=\frac{\text{Number of atoms}\times \text{mass of an atom}}{\text{molas mass of compound}}\times 100$

Percentage of carbon in an organic solid = 40.0%

$40\%=\frac{x\times 12 g/mol}{120.16 g/mol}\times 100$

x = 4.0

Percentage of hydrogen in an organic solid = 6.7%

$6.7\%=\frac{y\times 1 g/mol}{120.16 g/mol}\times 100$

y = 8.0

Percentage of hydrogen in an organic solid = 6.7%

$53.3\%=\frac{x\times 12 g/mol}{120.16 g/mol}\times 100$

y = 4.0

The molecular formula of an organic solid is $C_4H_8O_4$

8 0

3 years ago

What is the energy of a photon with:<br> a wavelength of 827 nm? What type of radiation is it?

xeze [42]

Explanation:

Given parameters:

Wavelength of photon = 827nm = 827 x 10⁻⁹m

Unknown:

Energy of the photon = ?

Type of radiation = ?

Solution:

The energy of a photon can be derived using the expression below:

E = $\frac{h c}{wavelength}$

h is the Planck's constant = 6.63 x 10⁻³⁴m²kg/s

c is the speed of light = 3 x 10⁸m/s

Insert the parameters and solve;

E = $\frac{6.63 x 10^{-34} x 3 x 10^{8} }{827x 10^{-9} }$

E = 2.4 x 10⁻¹⁹J

Type of radiation:

Near infrared radiation

7 0

2 years ago

Identify the Bronsted-Lowry acid, the Bronsted-Lowry base, the conjugate acid and the conjugate base for each of the following r

Vlad1618 [11]

Answer:

Acids → H₂CO₃ from equilibrium 1 and water, from equilibrium 2.

Bases → Water from equilibrium 1 and ammonia from equilibrium 2.

In 1st equilibrium, H₃O⁺ is the conjugate acid and HCO₃⁻ the conjugate base.

In 2nd equilibrium, NH₄⁺ is the conjugate acid, and OH⁻, the conjugate base.

Explanation:

By the Bronsted-Lowry you know that acids are the one that release protons and base are the ones that catch them.

For the first equilibrium:

H₂CO₃(aq) + H₂O(l) ⇄ H₃O⁺(aq) + HCO₃⁻(aq)

Carbonic acid is the acid → It donates the proton to water, so the water becomes the base. As H₂CO₃ is the acid, the bicarbonate is the conjugate base (it can accept the proton from water to become carbonic acid, again) and the hydronium is the conjugate acid (it would release the proton to become water).

For the second equilibrium:

NH₃(aq) + H₂O(l) ⇄ NH₄⁺ (aq) + OH⁻(aq)

This is the opposite situation → Water relase the proton to ammonia, that's why water is the acid and NH₃, the base (it accepted to become ammonium). The NH₄⁺ is the conjugate acid (it can release the H⁺ to become ammonia) and the OH⁻ is the conjugate base (It can accept the proton to become water, again).

5 0

3 years ago

What does it mean to control variables in an experiment ￼

What does it mean to control variables in an experiment