MgCl2
————not sure with the answer
Answer:
The correct answer is:
A solution feels warm after a cool solid is added to it (C)
Explanation:
Chemical changes among other results in a change of the temperature of the reactants, producing a product of higher temperature (exothermic reaction) or a product of lower temperature (endothermic reaction). In this case, the temperature of the product was higher than the reactants suggesting an exothermic reaction.
The other options however, suggests physical changes rather than a chemical changes;
A. the change of color of the water suggest mixing or water and color molecules.
B. solid changing into liquid is change of state, which is more of a physical change than chemical
D. Filtration is a physical process, hence the change is a physical change.
Answer:
Mass = 713.4 ×10⁻⁴ g
Explanation:
Given data:
Number of moles of calcium phosphate = 2.3×10⁻⁴ mol
Mass of calcium phosphate = ?
Solution:
Formula:
Number of moles = mass/molar mass
Molar mass of calcium phosphate is 310.18 g/mol
by putting values,
2.3×10⁻⁴ mol = mass / 310.18 g/mol
Mass = 2.3×10⁻⁴ mol × 310.18 g/mol
Mass = 713.4 ×10⁻⁴ g
The concentration (in M) of hydroxide ions in a solution at 25°C with a pOH of 3.58 is 2.6 × 10⁻⁴ M.
pOH is the measure of basic nature of a solution by evaluating the [OH⁻] concentration.
It is the negative logarithm of the hydroxide ion concentration.
Given,
pOH = 3.58
Temperature = 25°C = 298K
At 25°C, the relation of pOH and [OH⁻] concentration is as follows:
∴ pOH = -log [OH⁻]
⇒ 3.58 = -log [OH⁻]
⇒log [OH⁻] = -3.58
⇒ [OH⁻] = antilog (-3.58)
⇒[OH⁻] = 2.6 × 10⁻⁴ M
The concentration (in m) of hydroxide ions in a solution at 25.0 °C with a pOH of 3. 58 is 2.6 × 10⁻⁴ M.
Learn more about pOH here, brainly.com/question/17144456
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