Answer:
mass of Helium = mole of Helium x Molarmass of Helium
Explanation:
Mole of Helium = volume of Helium/ 22.4dm^3/mol
= 7.00 x 10^2/22.4
= 31.25mol
Mass of Helium = mole of Helium x Molarmass of Helium
= 31.25mol x 4g/mol
= 125g
Answer:

Explanation:
Given that,
Mass of the sample, m = 275 g
It required 10.75 kJ of heat to change its temperature from 21.2 °C to its melting temperature, 327.5 °C.
We need to find the specific heat of the metal. The heat required by a metal sample is given by :

c is specific heat of the metal

So, the specific heat of metal is
.
Answer:
Absolute error 
% Error
5
Explanation:
The absolute error is the the difference in the measured value and the actual value of a quantity.
Here the actual value is
grams
The measured value is
grams
Absolute error

Percent error

Where AE stands for absolute error and AV stands for absolute value.

%
Answer:
2370.0 contains 4 significant digits and Option (c) is correct .
1.20\times 10^{-3}\ contains\ three\ significant\ digit.
Option (b) is correct .
Step-by-step explanation:
Rules for finding significant digit .
1 : Non-zero digits are always significant.
2: Any zeros between two significant digits are significant .
3: Trailing zeros in the decimal number is also significant.
As the number given be 2,370.0.
= \frac{23700}{10}
Simplify the above
= 2370
Thus by using the rule given above.
2370.0 contains 4 significant digits.
Option (c) is correct .
As the number given be 0.00120 .
= \frac{120}{100000}
Simplify the above
= \frac{1.20}{1000}
= 1.20\times 10^{-3}
Thus by using the rule given above.
1.20\times 10^{-3}\ contains\ three\ significant\ digit.
Option (b) is correct .