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3 years ago

Does anyone know how to write a good hypothesis (If…then)

1 answer:

3 0

Here's an example of a hypothesis: If you increase the duration of light, (then) corn plants will grow more each day. The hypothesis establishes two variables, length of light exposure, and the rate of plant growth. An experiment could be designed to test whether the rate of growth depends on the duration of light

You might be interested in

What do agents such as chemicals, elevated temperatures, ionizing radiation, and viruses have in common?

Leni [432]

Answer:

All of them affect the DNA

Explanation:

Chemicals are compounds that can pass through cell membranes and modificate the DNA, elevated temperatures can denaturalize the cell and therefore damage the DNA, ionizing radiation can pass through cell organelles and reach the nucleus affecting the DNA, and viruses inject its DNA into the genome and modify it.

4 0

3 years ago

If the first isotope has a mass of 259.98 amu and a percent abundance of 35%, what is the percent abundance of the second isotop

brilliants [131]

If it is assumed that there are only two isotopes then the percent abundance needs to add up to 100%

100-35= 65%

The second isotope will have a 65% abundance.

7 0

3 years ago

8. How many atoms of cobalt are in a 0.39 mole sample of CoC

Debora [2.8K]

8.98

cobalt atoms

Explanation:

Avogadro's number

specifies

6.0221

individual particles. It is simply another collective number like a dozen, or a score, or a gross.

has the property that

6.0221

individual cobalt atoms has a mass of

58.93

⋅

. How did I know that? Did I have it memorized?

So the quantity is

≈

cobalt atoms.

3 0

3 years ago

Pls help me i dont know this

r-ruslan [8.4K]

Answer:

1. 12.6 moles

2. 8.95 moles

3. 2A + 5B → 3C

4. 48 moles

Explanation:

1. 2Fe + 3Cl₂ → 2FeCl₃

We assume the chlorine in excess. Ratio is 2:2

2 moles of Fe, can produce 2 moles of chloride

12.6 moles of Fe will produce 12.6 moles of chloride.

2. 2Fe + 3Cl₂ → 2FeCl₃

For the same reaction, first of all we need to convert the mass to moles:

500 g . 1mol / 55.85 g = 8.95 mol

As ratio is 2:2, the moles we have are the same, that the produced

4. The reaction for the combustion is:

2C₂H₆ (g) + 7O₂ (g) → 4CO₂ (g) + 6H₂O (l)

We assume the oxygen in excess.

Ratio is 2:6, so 2 mol of ethane produce 6 moles of water

Therefore 16 moles of ethane may produce (16 .6) / 2 = 48 moles

3 0

3 years ago

In this experiment we will be using a 0.05 M solution of HCl to determine the concentration of hydroxide (OH-) in a saturated so

gulaghasi [49]

Answer: The moles of hydroxide ions present in the sample is 0.0008 moles

Explanation:

To calculate the concentration of acid, we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is HCl.

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is $Ca(OH)_2$

We are given:

$n_1=1\\M_1=0.05M\\V_1=16mL\\n_2=2\\M_2=?M\\V_2=36.0mL$

Putting values in above equation, we get:

$1\times 0.05\times 16=2\times M_2\times 36\\\\M_2=\frac{1\times 0.05\times 16}{2\times 36}=0.011M$

To calculate the moles of hydroxide ions, we use the equation used to calculate the molarity of solution:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}$

Molarity of solution = 0.011 M

Volume of solution = 36.0 mL

Putting values in above equation, we get:

$0.011=\frac{\text{Moles of }Ca(OH)_2\times 1000}{36}\\\\\text{Moles of }Ca(OH)_2=\frac{0.011\times 36}{1000}=0.0004mol$

1 mole of calcium hydroxide produces 1 mole of calcium ions and 2 moles of hydroxide ions.

Moles of hydroxide ions = (0.0004 × 2) = 0.0008 moles

Hence, the moles of hydroxide ions present in the sample is 0.0008 moles

8 0

3 years ago