At first I thought it was c but then I checked And it’s either B or A? I’m thinking mostly A but good luck
Answer:
We need 69 grams of NaHCO3
Explanation:
Step 1: Data given
Volume = 550 mL = 0.550 L
Molarity H2SO4 = 0.75 M
Step 2: The balanced equation
H2SO4(aq) + 2NaHCO3(aq) → Na2SO4(aq) + 2H2O(l) + 2CO2(g)
Step 3: Calculate moles of H2SO4
Moles H2SO4 = molarity * volume
Moles H2SO4 = 0.75 M * 0.550 L
Moles H2SO4 = 0.4125 moles H2SO4
Step 4: Calculate moles NaHCO3
For 1 mol H2SO4 we need 2 moles NaHCO3 to produce 1 mol Na2SO4 and 2 moles H2O and 2 Moles CO2
For 0.4125 moles H2SO4 we need 2*0.4125 = 0.825 moles NaHCO3
Step 5: Calculate mass NaHCO3
Mass NaHCO3 = moles * molar mass
Mass NaHCO3 = 0.825 moles * 84.0 g/mol
Mass NaHCO3 = 69.3 grams ≈ 69 grams
We need 69 grams of NaHCO3
Answer:
Personally I think thatthr answer could be 5.38853503%, you can round it however you need.
Explanation:
There's a value of error between the noted square meters and the actual room's area. which is 4.23. Using the formula to get the percentage of error is getting the value (78.5 - 74.27 = 4.23) and dividing it by 78.5. Then just multiply it by 100 to get the percentage.
The answer is 6×10⁹ years.
K-Ar dating is radioactive dating method used to measure a time elapsed since the rock is cool enough to trap Ar after a radioactive decay of 40K to 40Ar. It can be expressed as:
where:
- elapsed time
- half-life of K40
- amount of K40
<span>
- amount of Ar40
</span>
We know that a half-life of K40 is 1.251<span>×10⁹ years:
</span>
We do not know absolute value of amount of K40 and Ar40, but we know percentage and can express them as following:
<span>
</span>
So:
⇒ t = <span>6×10⁹
</span>
Thus, the rock is old <span>6×10⁹ years.</span>
Answer: To describe an object’s motion, you must have a distance, km, mm, m, a speed, and time to show how long, seconds, minuets, hours, days.