Answer:
54.1 % Ca, 43.2 % O, 2.7% H
Explanation:
Molecular formula for calcium hydroxide is Ca(OH)₂
As we don't have a mass of Ca(OH)₂ to find out the percentage composition, we consider that the question refers to 1 mol of compound.
1 mol of hydroxide weighs 74.08 g
1 mol of hydroxide has 1 mol of Ca, therefore 40.08 g are Ca
2 moles of O therefore 32g are O
2 moles of H therefore 2 g are H
Percentage composition is known as (Mass of element/Total mass) . 100
(40.08 / 74.08) . 100 = 54.1 %
(32 / 74.08) . 100 = 43.2 %
(2 / 74.08) . 100 = 2.7%
im a smart one
I think its A. it cant be C or D b/c we are measuring the distance between Earth and Saturn, not the speed.
C: 12.0107 g/mol ≅ 12.00 g/mol
H: 1.00784 g/mol ≅ 1.008 g/mol
O: 15.999 g/mol ≅ 16.00 g/mol
n(molar mass of CH2O)= 180
n.30=180
n=6
molecular formula: c6h12o6 glucose
Answer: The final temperature is 
Explanation:
As we know that,
![m_1\times c_1\times (T_{final}-T_1)=-[m_2\times c_2\times (T_{final}-T_2)]](https://tex.z-dn.net/?f=m_1%5Ctimes%20c_1%5Ctimes%20%28T_%7Bfinal%7D-T_1%29%3D-%5Bm_2%5Ctimes%20c_2%5Ctimes%20%28T_%7Bfinal%7D-T_2%29%5D)
.................(1)
where,
q = heat absorbed or released
= mass of lead = 50 g
= mass of water = 75 g
= final temperature = ?
= temperature of lead = 
= temperature of water = 
= specific heat of lead = 
= specific heat of water= 
Now put all the given values in equation (1), we get
![50\times 0.11\times (T_{final}-373)=-[75\times 1.0\times (T_{final}-273)]](https://tex.z-dn.net/?f=50%5Ctimes%200.11%5Ctimes%20%28T_%7Bfinal%7D-373%29%3D-%5B75%5Ctimes%201.0%5Ctimes%20%28T_%7Bfinal%7D-273%29%5D)
Therefore, the final temperature of the mixture will be 279.8 K.
