Answer:
- <u>Dependent variable</u>
Explanation:
In a controlled <em>experiment </em>there will be one independent variable, one dependent variable, and some controlled or constant parameters.
The target of the expermiment is to tes how the dependent variable changes with the independent variable.
So, the scientist will change (manipulate) the independent variable and measure the dependent vabiales.
Here, the temperature will be manipulated (within a range), so this is the independent variable; the height of the cake is the variable whose behavior wants to be determined, so this is the dependent variable. Controlled variables or constants may include the mixture, the size of the pan, the time of cooking, the oven, among others.
Answer:
d. 12.3 grams of Al2O3
Explanation:
Based on the reaction:
4Al + 3O2 → 2Al2O3
<em>Where 4 moles of Al reacts in excess of oxygen to produce 2 moles of aluminium oxide.</em>
<em />
To solve this question we must find the moles of Aluminium. With these moles we can find the moles of aluminium oxide using the reaction:
<em>Moles Al -Molar mass: 26.9815g/mol-</em>
6.50g * (1mol / 26.9815g) = 0.241 moles Al
<em>Mass Al₂O₃ -Molar mass: 101.96g/mol-</em>
0.241 moles Al * (2 mol Al2O3 / 4 mol Al) = 0.120 moles Al2O3
0.120 moles Al2O3 * (101.96g / mol) =
12.3g of Al2O3 are produced.
Right answer is:
<h3>d. 12.3 grams of Al2O3
</h3>
Answer:
1.25 x 10^15Hz
Explanation:
c = frequency x wavelength
c is the speed of light, which is equal to 3.00 x 10^8 m / s
frequency = c /wavelength
= (3.00 x 10^8m /s) / (2.40 x 10^-5 cm x 1 m /100cm)
= (3.00 x 10^8 m/s) / 2.40 x 10^-7m
= 1.25 x 10^15/s 1 / s = 1Hz
So, the Frequency = 1.25 x 10^15Hz
I hope this helped :)
We will balance the equation in the following order: metals, amethals, carbon, hydrogen and oxygen (the most common order).
The metal present in the equation is Sr, which is already balanced (there are 1 on each side of the equation).
The amethal present in the equation is Cl. There is 2 Cl in the left side and only one in the right side. So, we will multiply the quantity of the molecule that contains Cl by 2. Doing this, we'll obtain:
Looking at the equation, we can see that it is now fully balanced. Hence, a balanced equation of the reaction is:
17.8 mL NaOH
<em>Step 1.</em> Write the chemical equation
Fe^(2+) + 2NaOH → Fe(OH)2 + 2Na^(+)
<em>Step 2.</em> Calculate the moles of Fe^(2+)
Moles of Fe^(2+) = 500 mL Fe^(2+) × [0.0230 mmol Fe^(2+)]/[1 mL Fe^(2+)]
= 11.50 mmol Fe^(2+)
<em>Step 3.</em> Calculate the moles of NaOH
Moles of NaOH = 11.50 mmol Fe^(2+) × [2 mmol NaOH]/[1 mmol Fe^(2+)]
= 23.00 mmol NaOH
<em>Step 4.</em> Calculate the volume of NaOH
Volume of NaOH = 23.00 mmol NaOH × (1 mL NaOH/1.29 mmol NaOH)
= 17.8 mL NaOH
