Answer:
52 da
Step-by-step explanation:
Whenever a question asks you, "How long to reach a certain concentration?" or something similar, you must use the appropriate integrated rate law expression.
The i<em>ntegrated rate law for a first-order reaction </em>is
ln([A₀]/[A] ) = kt
Data:
[A]₀ = 750 mg
[A] = 68 mg
t_ ½ = 15 da
Step 1. Calculate the value of the rate constant.
t_½ = ln2/k Multiply each side by k
kt_½ = ln2 Divide each side by t_½
k = ln2/t_½
= ln2/15
= 0.0462 da⁻¹
Step 2. Calculate the time
ln(750/68) = 0.0462t
ln11.0 = 0.0462t
2.40 = 0.0462t Divide each side by 0.0462
t = 52 da
Answer:
Here's what I get
Explanation:
1. Nickel sulfate
base + acid ⟶ salt + water
NiSO₄ is a salt of the base Ni(OH)₂ and the acid sulfuric acid.
Hydroxides of transition metals are insoluble; most sulfates are soluble.

2. Carbonate + acid
Most carbonates are insoluble.
They react with acids to form carbonic acid (H₂CO₃), which decomposes into water and carbon dioxide.

Answer:
They are more stable than alkanes
Explanation:
- <em><u>Alkenes</u></em><em><u> are a type of unsaturated hydrocarbons </u></em>which means they have a<u> double bond</u> in their structure, or lack maximum number of hydrogen atoms on each carbon.
- Alkenes have a general formula of CnH2n. They are called <u>unsaturated hydrocarbons</u> since they have a double bond. They are therefore less stable compared to alkanes and also are readily reactive.
Phosphorous has three lone electrons that need pairing. Similar to how carbon has 4 lone electrons, and forms CH4