Answer:
0.12 M hydrofluoric acid + 0.17 M potassium fluoride
Explanation:
To make a buffer, you must to have an aqueous mixture of a weak acid and its conjugate base or vice versa.
Knowing that:
0.32 M calcium chloride + 0.27 M sodium chloride: <em>is not a good buffer system </em>because CaCl₂ and NaCl are both salts.
0.35 M ammonia + 0.36 M calcium hydroxide <em>is not a good buffer system </em>because ammonia is a weak base but calcium hydroxide is a strong base
0.19 M barium hydroxide + 0.28 M barium chloride <em>is not a good buffer system </em>because Ba(OH)₂ is a strong base.
0.12 M hydrofluoric acid + 0.17 M potassium fluoride <em>is a good buffer system </em>because HF is a weak acid and KF (F⁻ in aqueous medium), is its conjugate base
0.20 M hydrobromic acid + 0.22 M sodium bromide <em>is not a good buffer system </em>because HBr is a strong acid.
Answer:
The products have a higher heat content than the reactants.
Explanation:
The statement above is not true for an exothermic reaction because in an exothermic reaction heat is released to the surroundings. This simply means that the total energy of the products is less than that of the reactants.
Answer:
Complex System
Explanation:
Given that, a descriptive scientific investigation is one of the three main types of investigation which formulates and quantify the natural phenomenon. This natural phenomenon oftentimes involves Complex System, such as microscopic organisms, thereby, scientists often make observations to understand the interacting parts of this COMPLEX SYSTEM
Hence, the right answer is a COMPLEX SYSTEM
<h3>You will pay $ 30876800</h3>
We'll begin by calculating the mass in ounce (oz) of a cube foot (ft³) of gold. This can be obtained as follow:
<h3 />
Density of gold = 19298 oz/ft³
Volume of gold = 1 ft³
<h3>Mass of gold =?</h3>
Density = mass /volume
19298 = mass / 1
<h3>Mass of gold = 19298 oz</h3>
Finally, we shall determine the cost of 19298 oz of gold. This can be obtained as follow:
1 oz = $ 1600
Therefore,
19298 oz = 19298 × 1600
19298 oz = $ 30876800
Therefore, a solid cube foot of gold (i.e 19298 oz) will cost $ 30876800
Learn more: brainly.com/question/15407624
Fluorite is harder than gypsum but softer than apatite. Thus, the correct option is B.
<h3>What is the hardness of any element?</h3>
The hardness of any element may be defined as the capability of a material to oppose the process of deformation and remains in actual shape precisely.
According to the table of hardness scales by Mohs, the increasing order of given hardness of given elements is as follows:
Gypsum < Fluorite < Apatite.
Therefore, Fluorite is harder than gypsum but softer than apatite. Thus, the correct option is B.
To learn more about the Hardness of elements, refer to the link:
brainly.com/question/23721736
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