Answer:
1) Endothermic.
2) 
3) 
Explanation:
Hello there!
1) In this case, for these calorimetry problems, we can realize that since the temperature decreases the reaction is endothermic because it is absorbing heat from the solution, that is why the temperature goes from 22.00 °C to 16.0°C.
2) Now, for the total heat released by the reaction, we first need to assume that all of it is released by the solution since it is possible to assume that the calorimeter is perfectly isolated. In such a way, it is also valid to assume that the specific heat of the solution is 4.184 J/(g°C) as it is mostly water, therefore, the heat released by the reaction is:
3) Finally, since the enthalpy of reaction is calculated by dividing the heat released by the reaction over the moles of the solute, in this case NH4Cl, we proceed as follows:
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Best regards!
<h3>Answer:</h3>
#1. Ca²⁺
# 2. Ca²⁺(aq) + SO₃²⁻(aq) → CaSO₄(s)
#3. 3Ag⁺(aq) + PO₄³⁻(aq) → Ag₃PO₄(s)
<h3>Explanation:</h3>
The question above concerns solubility of salts or ions in water.
The solution given contains Ag+, Ca2+, and Co2+ ions.
- In the first case, when Lithium bromide is added to the solution, there is no white precipitate formed.
- In the second case, the addition of Lithium sulfate results in the formation of a precipitate because of the Ca²⁺ in the solution combined with the SO₃²⁻ from lithium sulfate to form an insoluble CaSO₄.
- The net ionic equation for the reaction is;
Ca²⁺(aq) + SO₃²⁻(aq) → CaSO₄(s)
- From the solubility rules, all sulfates are soluble except BaSO₄, CaSO₄, and PbSO₄.
- In the third case, the addition of Lithium phosphate results in the formation of a precipitate because Ag⁺ ions in the solution combine with phosphate ions ( PO₄³⁻) from lithium phosphate to form an insoluble salt, Ag₃PO₄.
- The net ionic equation for the reaction is;
3Ag⁺(aq) + PO₄³⁻(aq) → Ag₃PO₄(s)
- According to solubility rules, all phosphates are insoluble in water except Na₃PO₄, K₃PO₄, and (NH₄)₃PO₄.
Answer:
The correct answer is -
FALSIFIABLE:
Aloe vera gel can heal wounds by boosting cell renewal.
Drinking aloe juice can reduce the risk of lung cancer.
NON-FALSIFIABLE:
Aloe vera gel is the best natural skin moisturizer.
Aloe vera juice tastes better than carrot juice.
Explanation:
Falsifiable is the ability or chances of any hypothesis, claim or statement to be proved wrong. In such a hypothesis, it is possible to carry an experimental observation that disproves the idea in claim or question.
In the given examples
Aloe vera gel can heal wounds by boosting cell renewal.
Drinking aloe juice can reduce the risk of lung cancer.
There is no observation in the favor of the claim so there more likely to be falsifiable whereas, Aloe vera gel is the best natural skin moisturizer.
Aloe vera juice tastes better than carrot juice are more non-falsifiable as these are based on personal choice or experimental observation.
The given reaction:
<span>ch3ch2cooh (aq) ↔ ch3ch2coo- (aq) + h+ (aq)
is called a reversible reaction.
This means that, the reaction does not reach an end point.
In this type of reactions, reactants react together to form products, while products combine together to form reactants.
So, the reaction proceeds in both direction forming both reactants and products.</span>
Explanation:
2H2O2 => 2H2O + O2
Moles of hydrogen peroxide = 0.150dm³ * (0.02mol/dm³) = 0.003mol .
Moles of oxygen = 0.0015mol.
Volume of oxygen = 0.0015mol * (22.4dm³/mol) = 0.0336dm³.
