It would be group 1, the alkali metals and group 17, the halogens.
Hope this helps! (:
All four answers are right 100%.
Answer:
used to date rocks and other objects based on the known decay rate of radioactive isotopes.
Explanation:
Different methods of radiometric dating can be used to estimate the age of a variety of natural and even man-made materials.
Answer:
![\boxed {\boxed {\sf 120 \ or \ 117 \ grams \ H_2O \ depending \ on \ significant \ figures }}](https://tex.z-dn.net/?f=%5Cboxed%20%7B%5Cboxed%20%7B%5Csf%20120%20%5C%20or%20%5C%20117%20%5C%20grams%20%5C%20H_2O%20%5C%20depending%20%5C%20on%20%5C%20significant%20%5C%20figures%20%7D%7D)
Explanation:
We want to convert from moles of water to grams of water.
First, find the molar mass of water (H₂O) Look on the Periodic Table for the masses of hydrogen and oxygen.
- Hydrogen (H): 1.008 g/mol
- Oxygen (O): 15.999 g/mol
Next, add up the number of each element in water. The subscript of 2 comes after the H, so there are 2 moles of hydrogen.
- 2 Hydrogen: (1.008 g/mol*2) = 2.016 g/mol
Finally, add the molar mass of 2 hydrogen and 1 oxygen.
- 2.016 g/mol (2 Hydrogen) + 15.999 g/mol (1 oxygen)= 18.015 g/mol
Next, find the grams in 6.5 moles.
Use the molar mass we just found as a ratio.
![molar \ mass \ ratio: \frac{18.015 \ g \ H_2O}{1 \ mol \ H_2O}](https://tex.z-dn.net/?f=molar%20%5C%20mass%20%5C%20ratio%3A%20%5Cfrac%7B18.015%20%5C%20g%20%5C%20H_2O%7D%7B1%20%5C%20mol%20%5C%20H_2O%7D)
We want to find the grams in 6.5 moles. We can multiply the ratio above by 6.5
![6.5 \ mol \ H_2O * \frac{18.015 \ g \ H_2O}{1 \ mol \ H_2O}](https://tex.z-dn.net/?f=6.5%20%5C%20mol%20%5C%20H_2O%20%2A%20%5Cfrac%7B18.015%20%5C%20g%20%5C%20H_2O%7D%7B1%20%5C%20mol%20%5C%20H_2O%7D)
Multiply. Note that the moles of H₂O will cancel each other out.
![6.5 * \frac{18.015 \ g \ H_2O}{1}](https://tex.z-dn.net/?f=6.5%20%2A%20%5Cfrac%7B18.015%20%5C%20g%20%5C%20H_2O%7D%7B1%7D)
![6.5 * {18.015 \ g \ H_2O}](https://tex.z-dn.net/?f=6.5%20%2A%20%7B18.015%20%5C%20g%20%5C%20H_2O%7D)
![117.0975 \ g \ H_2O](https://tex.z-dn.net/?f=117.0975%20%5C%20g%20%5C%20H_2O)
If we want to round to the technically correct significant figures, it would be 2 sig figs. The original measurement, 6.5, has 2 (6 and 5).
![\approx 120 \ g \ H_2O](https://tex.z-dn.net/?f=%5Capprox%20120%20%5C%20g%20%5C%20H_2O)
Answer:
0.013 mole
Explanation:
Step 1:
Data obtained from the question. This includes:
Volume (V) = 250 mL
Pressure (P) = 1.3 atm
Temperature (T) = 33°C
Number of mole of (n) =?
Step 2:
Conversion to appropriate units.
The volume and the temperature given in the question must be converted to their appropriate unit in order to obtain the answer to the question in the right unit.
For volume:
We must, convert mL to L
1000 mL = 1 L
Therefore, 250 mL = 250/1000 = 0.25 L
For temperature:
We, must convert °C to K.
K = °C + 273
K = 33°C + 273
K = 306K
Step 3:
Determination of the number of mole of CO2.
Applying the ideal gas equation:
PV = nRT
The number of mole of CO2 can be obtained as follow:
V = 0.25 L
P = 1.3 atm
T = 306K
R (gas constant) = 0.082atm.L/Kmol
Number of mole of (n) =?
PV = nRT
1.3 x 0.25 = n x 0.082 x 306
Divide both side by 0.082 x 306
n = (1.3 x 0.25) /(0.082 x 306)
n = 0.013 mole