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Tell me all about ‘Lead Bismuthate glass’
what’s its chemical properties
and chemical formula
Krypton-87 has rate constant of 1.5 x 10 -4 / s. What is the activity of a 2.0 mg sample?
- It requires two sticks of butter to make a batch of 20 cookies. How much butter will it take to make 150
cookies?
Noble gases are nonreactive and stable. Which of the following represents the valence electron configuration of noble gases in periods 2-7? *
has air pollution increased or decreased?
Given the average bond energies in kJ/mol: H-H = 436; Cl-Cl = 242; H-Cl = 431.
What is the energy change for the decomposition of hydrogen chloride? 2HCl -> H2 + Cl2
Is the decomposition of hydrogen chloride an exothermic or endothermic process? How do you know?
You burn 8.0 g of marshmallow to warm 400 mL of water. The temperature of the water increases from 20 degrees C to 80 degrees C
How many calories of heat are transferred to the water?
What is the calories per gram of marshmallow?
The label on the bag of marshmallows indicates that one 8-gram marshmallow has 24 kcal. How does this compare with your answer. Explain.
How much energy is released during the combustion of 24.0 g of methane, CH4. DeltaH = -90 kJ/mol.
The energy change for the reaction between hydrochloric acid and sodium hydroxide is -56 kJ/mol. Therefore....
a. the reaction is exothermic and the temperature increases
b. the reaction is exothermic and the temperature falls
c. the reaction is endothermic and the temperature rises
d. the reaction is endothermic and the temperature falls
Calcium carbonate (Caco,) which is found in limestone and marble reacts readily with hydrochloric acid (HCI) to produce calcium chloride (CaCl). carbon dioxide, and water.
a. Write the balanced chemical reaction:
b. What mass of hydrochloric acid will be needed to produce 325 g of
calcium chloride?
c. What mass of carbon dioxide could be produced if 750 g of calcium carbonate reacts with excess hydrochloric acid?
