Answer:
The independent variable is the condition that you change in an experiment. It is the variable you control.
Explanation:
It is called independent because its value does not depend on and is not affected by the state of any other variable in the experiment. Sometimes you may hear this variable called the "controlled variable" because it is the one that is changed.
Answer:
D) HCl(aq)
Explanation:
A homogeneous mixture can be defined as any liquid, solid or gaseous mixture which has an identical or uniform composition and properties throughout any given sample of the mixture. In Chemistry, all solutions are considered to be a homogeneous mixture.
In this scenario, the chemical formula which represents a homogeneous mixture is aqueous hydrogen chloride, HCl(aq). The aqueous hydrogen chloride is a homogeneous mixture of water and hydrogen chloride. This ultimately implies that, aqueous hydrogen chloride HCl(aq) is a solution of hydrogen chloride in water and it is commonly referred to as Hydrochloric acid.
Given by the chemical equation;
Answer:(4) ----accepts a proton
Explanation:
H2O water can produce both hydrogen and hydroxide ions
H2O --> H+ + OH-
According to the Bronsted-Lowry theory, it can be a proton donor and a proton acceptor.this means that It can donate a hydrogen ion to become its conjugate base, or can accept a hydrogen ion to form its conjugate acid,
When , a water molecule, H2O accepts a proton it will act as a Brønsted-Lowry base especially when dissolved in a strong acidic medium. for eg
HCl + H2O(l) → H3O+(aq) + Cl−(aq)
Here, Hydrochloric acid is a strong acid and ionizes completely in water, since it is more acidic than water, the water will act as a base.
Answer:

Explanation:
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In this case, since the equation we use to model the heat exchange into the calorimeter and compute the heat of reaction is:

We plug in the mass of water, temperature change and specific heat to obtain:

Now, this enthalpy of reaction corresponds to the combustion of propyne:

Whose enthalpy change involves the enthalpies of formation of propyne, carbon dioxide and water, considering that of propyne is the target:

However, the enthalpy of reaction should be expressed in kJ per moles of C3H4, so we divide by the appropriate moles in 7.00 g of this compound:

Now, we solve for the enthalpy of formation of C3H4 as shown below:

So we plug in to obtain (enthalpies of formation of CO2 and H2O are found on NIST data base):

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