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.
Answer: A. is prey B. is predator C. is habitat D. is comunity E. is plants are producers and plant eating animals consumors F. is food chain G. is food web H. parasite I decomposers and scavengers J. is compete K an adsption
Explanation:
Answer:
485.76 g of CO₂ can be made by this combustion
Explanation:
Combustion reaction:
2 C₄H₁₀(g) + 13 O₂ (g) → 8 CO₂ (g) + 10 H₂O (g)
If we only have the amount of butane, we assume the oxygen is the excess reagent.
Ratio is 2:8. Let's make a rule of three:
2 moles of butane can produce 8 moles of dioxide
Therefore, 2.76 moles of butane must produce (2.76 . 8)/ 2 = 11.04 moles of CO₂
We convert the moles to mass → 11.04 mol . 44g / 1 mol = 485.76 g
Answer:
3 protons and also 3 electrons
Explanation:
z=p=e
Answer: The original volume in liters was 0.0707L
Explanation:
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.
The combined gas equation is,
where,
= initial pressure of gas = 0.85 atm
= final pressure of gas = 456 mm Hg = 0.60 atm (760mmHg=1atm)
= initial volume of gas = ?
= final volume of gas = 94.0 ml
= initial temperature of gas = 
= final temperature of gas = 
Now put all the given values in the above equation, we get:
(1L=1000ml)
Thus the original volume in liters was 0.0707L
