Answer:
A. your observations in writing
Explanation:
Descriptive investigation is one of the mode of inquiries in science. It is devoid of the usual collection of data in the field or setting up laboratory experiments to compared variables.
- In descriptive investigation, observations are usually done in writing.
- They are usually common in Astrology.
- Such investigation involves a question without a hypothesis ensuing.
- Tests are usually not carried out in descriptive investigation.
Answer:
Approximately
.
Explanation:

The actual yield of
was given. The theoretical yield needs to be calculated from the quantity of the reactant.
Balance the equation for the hydrolysis of water:
.
Note the ratio between the coefficient of
and
:
.
This ratio will be useful for finding the theoretical yield of
.
Look up the relative atomic mass of hydrogen and oxygen on a modern periodic table.
Calculate the formula mass of
and
:
.
.
Calculate the number of moles of molecules in
of
:
.
Make use of the ratio
to find the theoretical yield of
(in terms of number of moles of molecules.)
.
Calculate the mass of that approximately
of
(theoretical yield.)
.
That would correspond to the theoretical yield of
(in term of the mass of the product.)
Given that the actual yield is
, calculate the percentage yield:
.
Answer:
My guess would be 12.5828
<span>Pentane has a boiling point of 36.1 C, while isopentane boils at 27.7C. Neopentane has the lowest boiling point at 9.5 C. Therefore from highest to lowest boiling points, it is pentane, isopentane, and neopentane.</span>
Given the following equation; Cu + 2AgNO3 = Cu(NO3)2 + 2Ag, 48.97 grams of Cu are needed to react with 262g of AgNO3.
<h3>How to calculate mass of substances?</h3>
The mass of a substance can be calculated using the following steps:
Cu + 2AgNO3 = Cu(NO3)2 + 2Ag
1 mole of Cu react with 2 moles of AgNO3
- Molar mass of AgNO3 = 169.87 g/mol
- Molar mass of Cu = 63.5g/mol
moles of AgNO3 = 262g/169.87g/mol = 1.54mol
1.54 moles of AgNO3 will react with 0.77 moles of Cu.
mass of Cu = 0.77 × 63.5 = 48.97g
Therefore, given the following equation; Cu + 2AgNO3 = Cu(NO3)2 + 2Ag, 48.97 grams of Cu are needed to react with 262g of AgNO3.
Learn more about mass at: brainly.com/question/6876669