Answer:
0.15g
Explanation:
Given parameters:
Number of molecules of water = 1.2 x 10²¹ molecules
Unknown:
Mass of SnO₂ = ?
Solution:
To solve this problem, we have to work from the known to the unknown specie;
SnO₂ + 2H₂ → Sn + 2H₂O
Ensure that the equation given is balanced;
Now,
the known species is water;
6.02 x 10²³ molecules of water = 1 mole
1.2 x 10²¹ molecules of water = 
= 0.2 x 10⁻²moles
Number of moles of water = 0.002moles
From the balanced chemical equation:
2 mole of water is produced from 1 mole of SnO₂
0.002 moles of water will be produced from 
= 0.001moles
To find the mass;
Mass = number of moles x molar mass
Molar mass of SnO₂ = 118.7 + 2(16) = 150.7g/mol
Mass = 0.001 x 150.7 = 0.15g
Answer: low temperature
Explanation:-
S.I or M.K.S is a system for defining physical units as meter, kilogram, second, ampere, kelvin or celcius, candela, and mole together with a set of prefixes to indicate multiplication or division by a power of ten for measuring length, mass, time , current, temperature and amount of substance respectively.
Given :
lake length = 563 kilometers = 
High temperature =
Low temperature =
annual precipitation =762 mm= 
Thus low temperature in units of Fahrenheit is not an S.I unit of measurement.
1) Find the number of mols of HCl in 5.2 liters of 4.0M solution:
n = M*V(L) = 4.0 mol/L * 5.2 L = 20.8 mol
2) Find the number of mols of Mg that will react with 20.8 mol of HCl, using the coefficients of the balanced equation
[1mol Mg / 2 mol HCl] * 20.8 mol HCl = 10.4 mol Mg
3) Transform mol to mass using the atomic mass:
10.4 mol Mg * 24.3 g/mol = 252.7 g of Mg.
Nonmetals form negatively charged ions, or anions. They do this because they need to gain one to three electrons in order to achieve an octet of valence electrons, making them isoelectronic with the noble gas at the end of the period to which they belong.
