Answer:
* No precipitate: 
* Precipitate: 
* Precipitate: 
Explanation:
Hello!
In this case, since these all are double displacement reactions, in which the cations and anions are exchanged, we can write the resulting chemical reactions as follows:
a. LiOH and NaCl: No precipitate is formed since LiOH and NaOH are both largely soluble in water:
b. BaCl2 and Na3PO4: barium phosphate precipitate is formed because it has a large molar mass which makes it insoluble in water:
c. MgSO4 and KOH: magnesium hydroxide "milky" precipitate is formed because it is not soluble in water:
Moreover, we can relate the solubility of a substance by considering its polarity, molar mass and nature; usually, heavy substances tend to be insoluble in water as well as nonpolar compounds.
Best regards!
Sugar burns in air.....................................
Answer:
4.14 x 10²⁴ molecules CO₂
Explanation:
2 C₄H₁₀ + 13 O₂ --> 8 CO₂ + 10 H₂O
To find the number of CO₂ molecules, you need to start with 100 grams of butane (C₄H₁₀), convert to moles (using the molar mass), convert to moles of CO₂ (using coefficients from equation), then convert to molecules (using Avagadro's number). The molar mass of C₄H₁₀ is calculated using the quantity of each element (subscript) multiplied by the number on the periodic table. The ratios should be arranged in a way that allows for units to be cancelled.
4(12.011g/mol) + 10(1.008 g/mol) = 58.124 g/mol C₄H₁₀
100 grams C₄H₁₀ 1 mol C₄H₁₀ 8 mol CO₂
-------------------------- x ---------------------- x ---------------------
58.124 g 2 mol C₄H₁₀
6.022 x 10²³ molecules
x ------------------------------------ = 4.14 x 10²⁴ molecules CO₂
1 mol CO₂
Answer: A) grinding coffee beans
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.
A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.
1. Grinding coffee : Only change in size takes place, thus a physical change
2. Baking a cake: the chemical reaction occurs by combination of flour with oxygen , thus a chemical change.
3.:converting water to hydrogen and oxygen: The decomposition iof water takes place, thus is a chemical change
4.Burning of coal: the chemical reaction occurs by combination of carbon with oxygen , thus a chemical change.
