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3 years ago

Question 1

1 answer:

4 0

Question 1Which of the following describes the treatment in an investigation?

the factor that is changed in order to observe a response

Question 2
Which statement best describes an independent variable?

The variable you change in an investigation

Question 3
Liam did an investigation to see how water temperature affects the amount of salt that will dissolve in the water. He filled 4 beakers with exactly 100 milliliters of water each. He then heated each beaker to a different temperature and tested salt solubility at each different temperature. What was Liam's independent variable?

the temperature of the water in each beaker

Question 4
Which of the following is an example of a treatment?

Changes made to the temperature of a greenhouse

Question 5
Jose is curious about which home remedy removes skunk smell from his dog. Which of the following is a variable that must be kept constant?

The home remedy used

Question 6
It is not important to make sure that all variables other than the independent variable are kept constant.

False

Question 7
In order to determine whether or not a substance is an acid or a base, you may stick your finger in the container and make your decision based on whether or not your finger feels slippery.
False

Question 8
A poison hazard symbol means your should not let chemicals contact your skin, ingest or inhale the substance.

True

Question 9
Repeating an experiment is important because

it reduces the chance of error

Question 10
When using repeated trials during a scientific investigation, scientists should find the average of their data for use in their final report.

True

You might be interested in

Which statememt describes gravity? Select three options

Fofino [41]

Gravity is a force which tries to pull two objects toward each other. Anything which has mass also has a gravitational pull. The more massive an object is, the stronger its gravitational pull is. Earth's gravity is what keeps you on the ground and what causes objects to fall.

8 0

4 years ago

A 18.5 gram sample of metal was added to a graduated cylinder that had

Virty [35]

Answer:

$d=2.15g/mL$

Explanation:

Hello there!

In this case, since the density of the metal is computed as shown below:

$d=\frac{m}{V}$

We need to calculate the volume of the solid by subtracting the final volume and the initial volume of water:

$V=54.10mL-45.50mL\\\\V=8.60mL$

Thus, we obtain:

$d=\frac{18.5g}{8.60mL}\\\\d=2.15g/mL$

Best regards!

7 0

3 years ago

The heat equation, as given in the introduction, can also be rearranged to calculate the mass or temperature change for a substa

notka56 [123]

Answer:

The correct answer is 281.39 grams.

Explanation:

To arrive at this answer you must first keep in mind the basic equation:

Q = m*Cp* ΔT

Now, in order to calculate the necessary aluminum mass that absorbs 2138 J when passing from 14.83 to 23.31 ° C you must "clear" m of the previous equation.

This means, leave only the mass on one side of the equation, and "pass" Cp and ΔT to the other side dividing Q. This would look like this:

m= Q/ (Cp*ΔT)

Then, you need the value of specific heat of aluminum in the correct units, that is J / g ° C, the approximate value is 0.896.

ΔT is calculated by doing the mathematical operation:

23.31 °C - 14.83 °C = 8.48 °C

Finally, the values of: Q (data provided in joules), Cp (J / g ° C) and ΔT (calculated in ° C) are replaced in the last equation and the mass (in grams) is calculated resulting in 281.39 grams.

3 0

4 years ago

The smell of dirty gym socks is caused by the compound caproic acid(contains H, C, O). Combustion of 0.844 g of caproic acid pro

adoni [48]

Answer: The molecular formula for the given organic compound is $C_2H_{32}O_4$

Explanation:

The chemical equation for the combustion of hydrocarbon having carbon, hydrogen and oxygen follows:

$C_xH_yO_z+O_2\rightarrow CO_2+H_2O$

where, 'x', 'y' and 'z' are the subscripts of Carbon, hydrogen and oxygen respectively.

We are given:

Mass of $CO_2=0.784g$

Mass of $H_2O=1.92g$

We know that:

Molar mass of carbon dioxide = 44 g/mol

Molar mass of water = 18 g/mol

For calculating the mass of carbon:

In 44 g of carbon dioxide, 12 g of carbon is contained.

So, in 0.784 g of carbon dioxide, $\frac{12}{44}\times 0.784=0.214g$ of carbon will be contained.

For calculating the mass of hydrogen:

In 18 g of water, 2 g of hydrogen is contained.

So, in 1.92 g of water, $\frac{2}{18}\times 1.92=0.213g$ of hydrogen will be contained.

Mass of oxygen in the compound = (0.844) - (0.214 + 0.213) = 0.417 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{0.214g}{12g/mole}=0.0134moles$

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{0.213g}{1g/mole}=0.213moles$

Moles of Oxygen = $\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{0.417g}{16g/mole}=0.0261moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.0134 moles.

For Carbon = $\frac{0.0134}{0.0134}=1$

For Hydrogen = $\frac{0.213}{0.0134}=15.89\approx 16$

For Oxygen = $\frac{0.0261}{0.0134}=1.95\approx 2$

Step 3: Taking the mole ratio as their subscripts.

The ratio of C : H : O = 1 : 16 : 2

The empirical formula for the given compound is $CH_{16}O_2$

For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.

The equation used to calculate the valency is:

$n=\frac{\text{Molecular mass}}{\text{Empirical mass}}$

We are given:

Mass of molecular formula = 116.2 g/mol

Mass of empirical formula = 60 g/mol

Putting values in above equation, we get:

$n=\frac{116.2g/mol}{60g/mol}=1.94\approx 2$

Multiplying this valency by the subscript of every element of empirical formula, we get:

$C_{(1\times 2)}H_{(16\times 2)}O_{(2\times 2)}=C_2H_{32}O_4$

Hence, the molecular formula for the given organic compound is $C_2H_{32}O_4$

5 0

3 years ago

Consider the balanced chemical equation below.

Doss [256]

Answer:

2.33 mol C

Explanation:

Step 1: Write the balanced generic chemical equation

3 A ⟶ C + 4 D

Step 2: Establish the appropriate molar ratio

According to the balanced equation, the molar ratio of A to C is 3:1.

Step 3: Calculate the number of moles of C produced from 7 moles of A

We will use the previously established molar ratio.

7 mol A × 1 mol C/3 mol A = 2.33 mol C

4 0

3 years ago